





Internet Engineering Task Force (IETF)                        R. Gellens
Request for Comments: 7852
Updates: 6443, 6881                                             B. Rosen
Category: Standards Track                                        NeuStar
ISSN: 2070-1721                                            H. Tschofenig

                                                             R. Marshall
                                         TeleCommunication Systems, Inc.
                                                         J. Winterbottom
                                             Winterb Consulting Services
                                                               July 2016


              Additional Data Related to an Emergency Call

Abstract

   When an emergency call is sent to a Public Safety Answering Point
   (PSAP), the originating device, the access network provider to which
   the device is connected, and all service providers in the path of the
   call have information about the call, the caller, or the location,
   which is helpful for the PSAP to have in handling the emergency.
   This document describes data structures and mechanisms to convey such
   data to the PSAP.  The intent is that every emergency call carry as
   much of the information described here as possible using the
   mechanisms described here.

   The mechanisms permit the data to be conveyed by reference (as an
   external resource) or by value (within the body of a SIP message or a
   location object).  This follows the tradition of prior emergency
   services standardization work where data can be conveyed by value
   within the call signaling (i.e., in the body of the SIP message) or
   by reference.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7852.




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Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   6
   3.  Document Scope  . . . . . . . . . . . . . . . . . . . . . . .   7
   4.  Data Structures . . . . . . . . . . . . . . . . . . . . . . .   7
    4.1.  Data Provider Information. . . . . . . . . . . . . . . . .   9
     4.1.1.  Data Provider String  . . . . . . . . . . . . . . . . .   9
     4.1.2.  Data Provider ID .  . . . . . . . . . . . . . . . . . .   9
     4.1.3.  Data Provider ID Series . . . . . . . . . . . . . . . .  10
     4.1.4.  Type of Data Provider . . . . . . . . . . . . . . . . .  11
     4.1.5.  Data Provider Contact URI . . . . . . . . . . . . . . .  12
     4.1.6.  Data Provider Language(s) Supported . . . . . . . . . .  13
     4.1.7.  xCard of Data Provider  . . . . . . . . . . . . . . . .  14
     4.1.8.  Subcontractor Principal . . . . . . . . . . . . . . . .  14
     4.1.9.  Subcontractor Priority  . . . . . . . . . . . . . . . .  15
     4.1.10. ProviderInfo Example  . . . . . . . . . . . . . . . . .  15
    4.2.  Service Information  . . . . . . . . . . . . . . . . . . .  18
     4.2.1.  Service Environment . . . . . . . . . . . . . . . . . .  18
     4.2.2.  Service Type  . . . . . . . . . . . . . . . . . . . . .  19
     4.2.3.  Service Mobility Environment .  . . . . . . . . . . . .  21
     4.2.4.  EmergencyCallData.ServiceInfo Example . . . . . . . . .  22
    4.3.  Device Information . . . . . . . . . . . . . . . . . . . .  22
     4.3.1.  Device Classification . . . . . . . . . . . . . . . . .  22
     4.3.2.  Device Manufacturer . . . . . . . . . . . . . . . . . .  23
     4.3.3.  Device Model Number . . . . . . . . . . . . . . . . . .  24
     4.3.4.  Unique Device Identifier  . . . . . . . . . . . . . . .  24
     4.3.5.  Device/Service-Specific Additional Data Structure . . .  25
     4.3.6.  Device/Service-Specific Additional Data Structure Type   26
     4.3.7.  EmergencyCallData.DeviceInfo Example  . . . . . . . . .  27
    4.4.  Owner/Subscriber Information . . . . . . . . . . . . . . .  27
     4.4.1.  Subscriber Data Privacy Indicator . . . . . . . . . . .  27
     4.4.2.  xCard for Subscriber's Data . . . . . . . . . . . . . .  28



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     4.4.3.  EmergencyCallData.SubscriberInfo Example  . . . . . . .  29
    4.5.  Comment  . . . . . . . . . . . . . . . . . . . . . . . . .  31
     4.5.1.  Comment . . . . . . . . . . . . . . . . . . . . . . . .  31
     4.5.2.  EmergencyCallData.Comment Example . . . . . . . . . . .  32
   5.  Issues with Getting New Types of Data into Use  . . . . . . .  32
    5.1.  Choosing between Defining a New Type of Block or a New
          Type of Device/Service-Specific Additional Data  . . . . .  33
   6.  Data Transport Mechanisms . . . . . . . . . . . . . . . . . .  33
    6.1.  Transmitting Blocks Using Call-Info  . . . . . . . . . . .  36
    6.2.  Transmitting Blocks by Reference Using the <provided-by>
          Element  . . . . . . . . . . . . . . . . . . . . . . . . .  37
    6.3.  Transmitting Blocks by Value Using the <provided-by>
          Element  . . . . . . . . . . . . . . . . . . . . . . . . .  38
    6.4.  The Content-Disposition Parameter  . . . . . . . . . . . .  39
   7.  Examples  . . . . . . . . . . . . . . . . . . . . . . . . . .  41
   8.  XML Schemas . . . . . . . . . . . . . . . . . . . . . . . . .  53
    8.1.  EmergencyCallData.ProviderInfo XML Schema  . . . . . . . .  54
    8.2.  EmergencyCallData.ServiceInfo XML Schema . . . . . . . . .  56
    8.3.  EmergencyCallData.DeviceInfo XML Schema  . . . . . . . . .  57
    8.4.  EmergencyCallData.SubscriberInfo XML Schema  . . . . . . .  59
    8.5.  EmergencyCallData.Comment XML Schema . . . . . . . . . . .  60
    8.6.  provided-by XML Schema . . . . . . . . . . . . . . . . . .  61
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  62
   10. Privacy Considerations  . . . . . . . . . . . . . . . . . . .  64
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  67
    11.1.  Emergency Call Additional Data Registry . . . . . . . . .  67
     11.1.1.  Provider ID Series Registry  . . . . . . . . . . . . .  67
     11.1.2.  Service Environment Registry . . . . . . . . . . . . .  68
     11.1.3.  Service Type Registry  . . . . . . . . . . . . . . . .  68
     11.1.4.  Service Mobility Registry  . . . . . . . . . . . . . .  68
     11.1.5.  Type of Provider Registry  . . . . . . . . . . . . . .  69
     11.1.6.  Device Classification Registry . . . . . . . . . . . .  69
     11.1.7.  Device ID Type Registry  . . . . . . . . . . . . . . .  69
     11.1.8.  Device/Service Data Type Registry  . . . . . . . . . .  70
     11.1.9.  Emergency Call Data Types Registry . . . . . . . . . .  70
    11.2.  'EmergencyCallData' Purpose Parameter Value . . . . . . .  72
    11.3.  URN Sub-Namespace Registration for <provided-by>
           Registry Entry  . . . . . . . . . . . . . . . . . . . . .  72
    11.4.  MIME Registrations  . . . . . . . . . . . . . . . . . . .  72
     11.4.1.  MIME Content-Type Registration for
              'application/EmergencyCallData.ProviderInfo+xml' . . .  72
     11.4.2.  MIME Content-Type Registration for
              'application/EmergencyCallData.ServiceInfo+xml'  . . .  73
     11.4.3.  MIME Content-Type Registration for
              'application/EmergencyCallData.DeviceInfo+xml' . . . .  74
     11.4.4.  MIME Content-Type Registration for
              'application/EmergencyCallData.SubscriberInfo+xml' . .  75




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     11.4.5.  MIME Content-Type Registration for
              'application/EmergencyCallData.Comment+xml'  . . . . .  76
    11.5.  URN Sub-Namespace Registration  . . . . . . . . . . . . .  78
     11.5.1.  Registration for
              urn:ietf:params:xml:ns:EmergencyCallData . . . . . . .  78
     11.5.2.  Registration for
              urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo . 78
     11.5.3.  Registration for
              urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo  . 79
     11.5.4.  Registration for
              urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo . . 80
     11.5.5.  Registration for
              urn:ietf:params:xml:ns:EmergencyCallData:SubscriberInfo 81
     11.5.6.  Registration for
              urn:ietf:params:xml:ns:EmergencyCallData:Comment . . .  81
    11.6.  Schema Registrations  . . . . . . . . . . . . . . . . . .  82
    11.7.  vCard Parameter Value Registration  . . . . . . . . . . .  83
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  84
    12.1.  Normative References  . . . . . . . . . . . . . . . . . .  84
    12.2.  Informative References  . . . . . . . . . . . . . . . . .  85
   Appendix A.  XML Schema for vCard/xCard . . . . . . . . . . . . .  89
   Appendix B.  XML Validation . . . . . . . . . . . . . . . . . . . 111
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 112
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . 113

1.  Introduction

   When an IP-based emergency call is initiated, a rich set of data from
   multiple data sources is conveyed to the Public Safety Answering
   Point (PSAP).  This data includes information about the calling party
   identity, the multimedia capabilities of the device, the request for
   emergency services, location information, and metadata about the
   sources of the data.  In addition, the device, the access network
   provider, and any service provider in the call path has even more
   information that is useful for a PSAP when handling an emergency.

   This document extends the basic set of data communicated with an
   emergency call based on the Session Initiation Protocol (SIP), as
   described in RFC 6443 [RFC6443] and RFC 6881 [RFC6881], in order to
   carry additional data that is useful to an entity or call taker
   handling the call.  This data is "additional" to the basic
   information found in the emergency call signaling used.  The intent
   is that every emergency call carry as much of the information
   described here as possible using the mechanisms described here.







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   This document defines three categories of this additional data that
   can be transmitted with an emergency call:

   Data Associated with a Location:  Primary location data is conveyed
      in the Presence Information Data Format Location Object (PIDF-LO)
      data structure as defined in RFC 4119 [RFC4119] and extended by
      RFC 5139 [RFC5139] and RFC 6848 [RFC6848] (for civic location
      information), RFC 5491 [RFC5491] and RFC 5962 [RFC5962] (for
      geodetic location information), and RFC 7035 [RFC7035] (for
      relative location).  This primary location data identifies the
      location or estimated location of the caller.  However, there
      might exist additional, secondary data that is specific to the
      location, such as floor plans, tenant and building owner contact
      data, heating, ventilation, and air conditioning (HVAC) status,
      etc.  Such secondary location data is not included in the location
      data structure but can be transmitted using the mechanisms defined
      in this document.  Although this document does not define any
      structures for such data, future documents can do so following the
      procedures defined here.

   Data Associated with a Call:  While some information is carried in
      the call setup procedure itself (as part of the SIP headers as
      well as in the body of the SIP message), there is additional data
      known by the device making the call, the access network to which
      the device is connected, and service providers along the path of
      the call.  This information includes service provider contact
      information, subscriber identity and contact information, the type
      of service the service provider and the access network provide,
      what type of device is being used, etc.  Some data is broadly
      applicable, while other data is dependent on the type of device or
      service.  For example, a medical monitoring device might have
      sensor data.  The data structures defined in this document (Data
      Provider Information, Device Information, and Owner/Subscriber
      Information) all fall into the category of "Data Associated with a
      Call".  Note that the owner/subscriber information includes the
      subscriber's vCard, which might contain personal information such
      as birthday, anniversary, etc., but the data block itself is still
      considered to be about the call, not the caller.

   Data Associated with a Caller:  This is personal data about a caller,
      such as medical information and emergency contact data.  Although
      this document does not define any structures within this category,
      future documents can do so following the procedures defined here.

   While this document defines data structures only within the category
   of Data Associated with a Call, by establishing the overall framework
   of Additional Data, along with general mechanisms for transport of
   such data, extension points, and procedures for future extensions, it



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   minimizes the work needed to carry data in the other categories.
   Other specifications can make use of the facilities provided here.

   For interoperability, there needs to be a common way for the
   information conveyed to a PSAP to be encoded and identified.
   Identification allows emergency services authorities to know during
   call processing which types of data are present and to determine if
   they wish to access it.  A common encoding allows the data to be
   successfully accessed.

   This document defines an extensible set of data structures, and
   mechanisms to transmit this data either by value or by reference,
   either in the SIP call signaling or in the PIDF-LO.  The data
   structures are usable by other communication systems and transports
   as well.  The data structures are defined in Section 4, and the
   transport mechanisms (using SIP and HTTPS) are defined in Section 6.

   Each data structure described in this document is encoded as a
   "block" of information.  Each block is an XML structure with an
   associated Multipurpose Internet Mail Extensions (MIME) media type
   for identification within transport such as SIP and HTTPS.  The set
   of blocks is extensible.  Registries are defined to identify the
   block types that can be used and to allow blocks to be included in
   emergency call signaling.

   Much of the information supplied by service providers and devices is
   private and confidential.  Service providers and devices generally go
   to lengths to protect this information; disclosing it in the context
   of an emergency call is a trade-off to protect the greater interest
   of the customer in an emergency.

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

   This document also uses terminology from [RFC5012].  We use the term
   "service provider" to refer to an Application Service Provider (ASP).
   A Voice Service Provider (VSP) is a special type of ASP.  With the
   term "Access Network Provider", we refer to the Internet Access
   Provider (IAP) and the Internet Service Provider (ISP) without
   further distinguishing these two entities, since the difference
   between the two is not relevant for this document.  Note that the
   roles of an ASP and access network provider might be provided by a
   single company.  An Emergency Services Provider is an entity directly
   involved in providing emergency services.  This includes PSAPs,




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   dispatch, police, fire, emergency medical, other responders, and
   other similar agencies.

   Within each data block definition (see Section 4), the values for the
   'Use:' label are specified as one of the following:

   'Required':  means it MUST be present in the data structure.

   'Conditional':  means it MUST be present if the specified
      condition(s) is met.  It MAY be present if the condition(s) is not
      met.

   'Optional':  means it MAY be present.

   vCard [RFC6350] is a data format for representing and exchanging a
   variety of information about individuals and other entities.  For
   applications that use XML, the format defined in vCard is not
   immediately applicable.  For this reason, an XML-based encoding of
   the information elements defined in the vCard specification has been
   defined, and the name of that specification is xCard [RFC6351].
   Since the term vCard is more familiar to most readers, we use the
   terms xCard and vCard interchangeably.

3.  Document Scope

   The scope of this document is explicitly limited to emergency calls.
   The data structures defined here are not appropriate to be conveyed
   in non-emergency calls because they carry sensitive and private data.
   However, in certain private-use situations between a specialized
   service provider (such as a vehicle telematics service provider) and
   dedicated equipment (such as in a vehicle) where the endpoints have a
   preexisting relationship and privacy issues are addressed within the
   relationship, the mechanisms and data structures defined here can be
   used with communications within the limited context of the
   preexisting relationship.

4.  Data Structures

   This section defines the following five data structures, each as a
   data block.  For each block, we define the MIME media type and the
   XML encoding.  The five data structures are:

   'Data Provider':  This block supplies name and contact information
      for the entity that created the data.  Section 4.1 provides the
      details.

   'Service Information':  This block supplies information about the
      service.  The description can be found in Section 4.2.



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   'Device Information':  This block supplies information about the
      device placing the call.  Device information can be found in
      Section 4.3.

   'Owner/Subscriber':  This block supplies information about the owner
      of the device or about the subscriber.  Details can be found in
      Section 4.4.

   'Comment':  This block provides a way to supply free form human-
      readable text to the PSAP or emergency responders.  This simple
      structure is defined in Section 4.5.

   Each block contains a mandatory <DataProviderReference> element.  The
   purpose of the <DataProviderReference> element is to associate all
   blocks added by the same data provider as a unit.  The
   <DataProviderReference> element associates the data provider block to
   each of the other blocks added as a unit.  Consequently, when a data
   provider adds additional data to an emergency call (such as device
   information), it MUST add information about itself (via the data
   provider block), and the blocks added contain the same value in the
   <DataProviderReference> element.  All blocks added by a single entity
   at the same time MUST have the same <DataProviderReference> value.
   (In certain situations, the same provider might process a call more
   than once, likely in different roles, and in such cases, each time it
   processes the call, it adds a new set of blocks with a new
   <DataProviderReference> value.)  The value of the
   <DataProviderReference> element has the same syntax and properties
   (specifically, world-uniqueness) as the value of the 'Message-ID'
   message body header field specified in RFC 5322 [RFC5322] except that
   the <DataProviderReference> element is not enclosed in brackets (the
   '<' and '>' symbols are omitted).  In other words, the value of a
   <DataProviderReference> element is syntactically a msg-id as
   specified in RFC 5322 [RFC5322].

   Each block is added to the "Additional Data Blocks" registry created
   in Section 11.1.9 and categorized as providing data about the caller.
   New blocks added to the registry in the future MUST also be
   categorized per the description of the three categories in Section 1.
   See Sections 5 and 5.1 for additional considerations when adding new
   blocks or types of data.

   Note that the xCard format is reused in some of the data structures
   to provide contact information.  In an xCard, there is no way to
   specify a 'main' telephone number (that is, a primary or main contact
   number, typically of an enterprise, as opposed to a direct-dial
   number of an individual).  These numbers are useful to emergency
   responders who are called to a large enterprise.  This document adds
   a new parameter value called 'main-number' to the 'TYPE' parameter of



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   the 'tel' property.  It can be used in any xCard in an emergency call
   additional data block.

4.1.  Data Provider Information

   This block is intended to be supplied by any service provider in the
   path of the call, or the access network provider, and the device.  It
   includes identification and contact information.  This block MUST be
   supplied by any entity that provides any other block; it SHOULD be
   supplied by every service provider in the call path and by the access
   network provider if those entities do not add any other blocks.
   Devices SHOULD use this block to provide identifying information.
   The MIME media type is 'application/
   EmergencyCallData.ProviderInfo+xml'.  An access network provider
   SHOULD provide this block either by value or by reference in the
   <provided-by> element of a PIDF-LO.

4.1.1.  Data Provider String

   Data Element:  Data Provider String

   Use:  Conditional.  Optional for blocks supplied by the originating
      device; mandatory otherwise.

   XML Element:  <DataProviderString>

   Description:  This is a plaintext string suitable for displaying the
      name of the service provider that supplied the data structure.  If
      the device creates the structure, it SHOULD use the value of the
      contact header field in the SIP INVITE.

   Reason for Need:  Inform the call taker of the identity of the entity
      providing the data.

   How Used by Call Taker:  Allows the call taker to interpret the data
      in this structure.  The source of the information often influences
      how the information is used, believed, or verified.

4.1.2.  Data Provider ID

   Data Element:  Data Provider ID

   Use:  Conditional.  Optional for blocks supplied by the originating
      device; mandatory otherwise.  This data MUST be provided by all
      entities other than the originating device in order to uniquely
      identify the service provider or access provider.

   XML Element:  <ProviderID>



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   Description:  A jurisdiction-specific code for, or the fully
      qualified domain name of, the access network provider or service
      provider shown in the <DataProvidedBy> element that created the
      structure.  NOTE: The value SHOULD be assigned by an organization
      appropriate for the jurisdiction.  In the United States, if the
      provider is registered with NENA, the provider's NENA Company ID
      MUST appear here.  Additional information can be found at the
      National Emergency Number Association (NENA) Company Identifier
      Program <http://www.nena.org/?page=cid2014> or the NENA Company ID
      <http://www.nena.org/?page=CompanyID>.  The NENA Company ID MUST
      be in the form of a URI in the following format:
      urn:nena:companyid:<NENA Company ID>.  If the organization does
      not have an identifier registered with a jurisdiction-specific
      emergency services registrar (such as NENA), then the value MAY be
      the fully qualified domain name of the service provider or access
      provider.  The device MAY use its IP address or fully qualified
      domain name (and set the 'Data Provider ID Series' element to
      'domain').

   Reason for Need:  Inform the call taker of the identity of the entity
      providing the data.

   How Used by Call Taker:  Where jurisdictions have lists of providers,
      the Data Provider ID provides useful information about the data
      source.  The Data Provider ID uniquely identifies the source of
      the data, which might be needed especially during unusual
      circumstances and for routine logging.

4.1.3.  Data Provider ID Series

   Data Element:  Data Provider ID Series

   Use:  Conditional.  Optional for blocks supplied by the originating
      device; mandatory otherwise.

   XML Element:  <ProviderIDSeries>

   Description:  Identifies the issuer of the <ProviderID>.  The
      "Provider ID Series" registry created in Section 11.1.1 initially
      contains the entries shown in Figure 1.

   Reason for Need:  Identifies how to interpret the Data Provider ID.
      The combination of ProviderIDSeries and ProviderID MUST be
      globally unique.

   How Used by Call Taker:  Determines which provider ID registry to
      consult for more information.




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      +-----------+--------------------------+----------------------+
      | Name      | Source                   | URL                  |
      +-----------+--------------------------+----------------------+
      | NENA      | National Emergency       | http://www.nena.org  |
      |           | Number Association       |                      |
      |           |                          |                      |
      | EENA      | European Emergency       | http://www.eena.org  |
      |           | Number Association       |                      |
      |           |                          |                      |
      | domain    | (The ID is a fully       | (not applicable)     |
      |           | qualified domain name)   |                      |
      +-----------+--------------------------+----------------------+

                   Figure 1: Provider ID Series Registry

4.1.4.  Type of Data Provider

   Data Element:  Type of Data Provider

   Use:  Required

   XML Element:  <TypeOfProvider>

   Description:  Identifies the type of data provider supplying the
      data.  The registry containing all valid values is created in
      Section 11.1.5, and the initial set of values is shown in
      Figure 2.

   Reason for Need:  Identifies the category of data provider.

   How Used by Call Taker:  This information can be helpful when
      deciding whom to contact when further information is needed.



















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   +------------------------------+------------------------------------+
   | Token                        | Description                        |
   +------------------------------+------------------------------------+
   |Client                        | Originating client/device          |
   |                              |                                    |
   |Access Network Provider       | Access network service provider    |
   |                              |                                    |
   |Telecom Provider              | Telecom service provider (including|
   |                              |    native and over-the-top VoIP    |
   |                              |    services)                       |
   |                              |                                    |
   |Telematics Provider           | A sensor-based service provider,   |
   |                              |    especially vehicle based        |
   |                              |                                    |
   |Language Translation Provider | A spoken language translation      |
   |                              |    service                         |
   |                              |                                    |
   |Emergency Service Provider    | An emergency service provider      |
   |                              |    conveying information to another|
   |                              |    emergency service provider      |
   |                              |                                    |
   |Emergency Modality Translation| An emergency-call-specific         |
   |                              |    modality translation service,   |
   |                              |    e.g., for sign language         |
   |                              |                                    |
   |Relay Provider                | An interpretation service, e.g.,   |
   |                              |    video relay for sign language   |
   |                              |    interpretation                  |
   |                              |                                    |
   |Other                         | Any other type of service provider |
   +------------------------------+------------------------------------+

                 Figure 2: Type of Data Provider Registry

4.1.5.  Data Provider Contact URI

   Data Element:  Data Provider Contact URI

   Use:  Required

   XML Element:  <ContactURI>

   Description:  When provided by a service provider or an access
      network provider, this information is expected to be a URI to a
      24/7 support organization tasked to provide PSAP support for this
      emergency call.  When provided by a device, this MUST be the
      contact information of the user or owner of the device.  (Ideally,
      this is the contact information of the device user, but when the



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      owner and user are separate (e.g., the device owner is an
      organization), this MAY be the contact information of the owner.)
      The Data Provider Contact URI SHOULD be a tel URI [RFC3966] in
      E.164 format and fully specified with a country code.  If a tel
      URI is not available, a generic SIP URI is acceptable.  Note that
      this contact information is not used by PSAPs for callbacks (a
      call from a PSAP directly related to a recently terminated
      emergency call, placed by the PSAP using a SIP Priority header
      field set to 'psap-callback', as described in [RFC7090]).

   Reason for Need:  Additional data providers might need to be
      contacted in error cases or other unusual circumstances.

   How Used by Call Taker:  To contact the supplier of the additional
      data for assistance in handling the call.

4.1.6.  Data Provider Language(s) Supported

   Data Element:  Data Provider Language(s) supported

   Use:  Required

   XML Element:  <Language>

   Description:  This field encodes the language used by the entity at
      the Data Provider Contact URI.  The content of this field consists
      of a single token from the Language Subtag Registry, which can be
      found at [LanguageSubtagRegistry], and is defined in [RFC5646].
      Multiple instances of this element MAY occur, but the order is
      significant and the preferred language SHOULD appear first.  The
      content MUST reflect the languages supported at the contact URI.

      (Note that this field informs the PSAP of the language(s) used by
      the data provider.  If the PSAP needs to contact the data
      provider, it can be helpful to know in advance the language(s)
      used by the data provider.  If the PSAP uses a communication
      protocol to reach the data provider, that protocol might have
      language facilities of its own (such as the 'language' media
      feature tag, defined in RFC 3840 [RFC3840], and the more extensive
      language negotiation mechanism proposed in [HUMAN-LANG]), and if
      so, those are independent of this field.)

   Reason for Need:  This information indicates if the emergency service
      authority can directly communicate with the service provider or if
      an interpreter will be needed.






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   How Used by Call Taker:  If the call taker cannot speak any language
      supported by the service provider, a translation service will need
      to be added to the conversation.  Alternatively, other persons at
      the PSAP, besides the call taker, might be consulted for help
      (depending on the urgency and the type of interaction).

4.1.7.  xCard of Data Provider

   Data Element:  xCard of Data Provider

   Use:  Optional

   XML Element:  <DataProviderContact>

   Description:  Per [RFC6351], the xCard structure is represented
      within a <vcard> element.  Although multiple <vcard> elements can
      be contained in a structure, only one <vcard> element SHOULD be
      provided.  If more than one appears, the first SHOULD be used.
      There are many fields in the xCard, and the creator of the data
      structure is encouraged to provide all available information.  N,
      ORG, ADR, TEL, and EMAIL are suggested at a minimum.  N SHOULD
      contain the name of the support group or device owner as
      appropriate.  If more than one TEL property is provided, a
      parameter from the "vCard Property Values" registry SHOULD be
      specified for each TEL.  For encoding of the vCard, this
      specification uses the XML-based encoding specified in [RFC6351],
      which is referred to in this document as 'xCard'.

   Reason for Need:  Information needed to determine additional contact
      information.

   How Used by Call Taker:  Assists the call taker by providing
      additional contact information aside from what is included in the
      SIP INVITE or the PIDF-LO.

4.1.8.  Subcontractor Principal

   When the entity providing the data is a subcontractor, the Data
   Provider Type is set to that of the primary service provider, and
   this entry is supplied to provide information regarding the
   subcontracting entity.

   Data Element:  Subcontractor Principal

   Use:  Conditional.  This data is required if the entity providing the
      data is a subcontractor.

   XML Element:  <SubcontractorPrincipal>



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   Description:  Some providers outsource their obligations to handle
      aspects of emergency services to specialized providers.  If the
      data provider is a subcontractor to another provider, this element
      contains the DataProviderString of the service provider to
      indicate which provider the subcontractor is working for.

   Reason for Need:  Identify the entity the subcontractor works for.

   How Used by Call Taker:  Allows the call taker to understand what the
      relationship is between data providers and the service providers
      in the path of the call.

4.1.9.  Subcontractor Priority

   Data Element:  Subcontractor Priority

   Use:  Conditional.  This data is required if the entity providing the
      data is a subcontractor.

   XML Element:  <SubcontractorPriority>

   Description:  If the subcontractor is supposed to be contacted first,
      then this element MUST have the value 'sub'.  If the provider the
      subcontractor is working for is supposed to be contacted first,
      then this element MUST have the value 'main'.

   Reason for Need:  Inform the call taker whom to contact first, if
      support is needed.

   How Used by Call Taker:  To decide which entity to contact first if
      assistance is needed.

4.1.10.  ProviderInfo Example

   <?xml version="1.0" encoding="UTF-8"?>
   <ad:EmergencyCallData.ProviderInfo
       xmlns:ad="urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo">
       <ad:DataProviderReference>string0987654321@example.org
       </ad:DataProviderReference>
       <ad:DataProviderString>Example VoIP Provider
       </ad:DataProviderString>
       <ad:ProviderID>urn:nena:companyid:ID123</ad:ProviderID>
       <ad:ProviderIDSeries>NENA</ad:ProviderIDSeries>
       <ad:TypeOfProvider>Telecom Provider</ad:TypeOfProvider>
       <ad:ContactURI>tel:+1-201-555-0123</ad:ContactURI>
       <ad:Language>en</ad:Language>
       <ad:DataProviderContact
           xmlns="urn:ietf:params:xml:ns:vcard-4.0">



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                   <vcard>
                       <fn><text>Hannes Tschofenig</text></fn>
                       <n>
                           <surname>Hannes</surname>
                           <given>Tschofenig</given>
                           <additional/>
                           <prefix/>
                           <suffix>Dipl. Ing.</suffix>
                       </n>
                       <bday><date>--0203</date></bday>
                       <anniversary>
                           <date-time>20090808T1430-0500</date-time>
                       </anniversary>
                       <gender><sex>M</sex></gender>
                       <lang>
                           <parameters><pref><integer>1</integer></pref>
                           </parameters>
                           <language-tag>de</language-tag>
                       </lang>
                       <lang>
                           <parameters><pref><integer>2</integer></pref>
                           </parameters>
                           <language-tag>en</language-tag>
                       </lang>
                       <org>
                           <parameters><type><text>work</text></type>
                           </parameters>
                           <text>Example VoIP Provider</text>
                       </org>
                       <adr>
                           <parameters>
                               <type><text>work</text></type>
                               <label><text>Hannes Tschofenig
                                   Linnoitustie 6
                                   Espoo , Finland
                                   02600</text></label>
                           </parameters>
                           <pobox/>
                           <ext/>
                           <street>Linnoitustie 6</street>
                           <locality>Espoo</locality>
                           <region>Uusimaa</region>
                           <code>02600</code>
                           <country>Finland</country>
                       </adr>
                       <tel>
                           <parameters>
                               <type>



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                                   <text>work</text>
                                   <text>voice</text>
                               </type>
                           </parameters>
                           <uri>tel:+358 50 4871445</uri>
                       </tel>
                       <tel>
                           <parameters>
                               <type>
                                   <text>work</text>
                                   <text>main-number</text>
                                   <text>voice</text>
                               </type>
                           </parameters>
                           <uri>tel:+358 50 5050505</uri>
                       </tel>
                       <email>
                           <parameters><type><text>work</text></type>
                           </parameters>
                           <text>hannes.tschofenig@nsn.com</text>
                       </email>
                       <geo>
                           <parameters><type><text>work</text></type>
                           </parameters>
                           <uri>geo:60.210796,24.812924</uri>
                       </geo>
                       <key>
                           <parameters><type><text>home</text></type>
                           </parameters>
                           <uri>
                             http://www.example.com/key.asc
                           </uri>
                       </key>
                       <tz><text>Finland/Helsinki</text></tz>
                       <url>
                           <parameters><type><text>home</text></type>
                           </parameters>
                           <uri>http://www.tschofenig.priv.at</uri>
                       </url>
                   </vcard>
       </ad:DataProviderContact>
   </ad:EmergencyCallData.ProviderInfo>

             Figure 3: EmergencyCallData.ProviderInfo Example







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4.2.  Service Information

   This block describes the service that the service provider provides
   to the caller.  It SHOULD be included by all service providers in the
   path of the call.  The MIME media type is 'application/
   EmergencyCallData.ServiceInfo+xml'.

4.2.1.  Service Environment

   Data Element:  Service Environment

   Use:  Conditional.  Required unless the 'ServiceType' value is
      'wireless'.

   XML Element:  <ServiceEnvironment>

   Description:  This element indicates whether a call is from a
      business or residence.  Currently, the only valid entries are
      'Business', 'Residence', and 'Unknown', as shown in Figure 4.  New
      values can be defined via the registry created in Section 11.1.2.

   Reason for Need:  To provide context and a hint when determining
      equipment and manpower requirements.

   How Used by Call Taker:  Information can be used to provide context
      and a hint to assist in determining equipment and manpower
      requirements for emergency responders.  This is non-authoritative;
      there are situations where the service provider does not know the
      type of service (e.g., anonymous prepaid service).  The type of
      service does not necessarily reflect the nature of the premises
      (e.g., a business line installed in a residence or cellular
      service).  The registry does not contain all possible values for
      all situations.  Hence, this is at best advisory information, but
      since it mimics a similar capability in some current emergency
      calling systems (e.g., a field in the Automatic Location
      Information (ALI) used with legacy North American wireline
      systems), it is known to be valuable to PSAPs.  The service
      provider uses its best information (such as a rate plan,
      facilities used to deliver service, or a service description) to
      determine the information and is not responsible for determining
      the actual characteristics of the location from which the call
      originated.  Because the usefulness is unknown (and less clear)
      for cellular, this element is OPTIONAL for commercial mobile radio
      services (e.g., cellular) and REQUIRED otherwise.







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                  +-----------+--------------------------+
                  | Token     | Description              |
                  +-----------+--------------------------+
                  | Business  | Business service         |
                  |           |                          |
                  | Residence | Residential service      |
                  |           |                          |
                  | Unknown   | Type of service unknown  |
                  |           |    (e.g., anonymous pre- |
                  |           |    paid service)         |
                  +-----------+--------------------------+

                  Figure 4: Service Environment Registry

4.2.2.  Service Type

   Data Element:  Service Delivered by Provider to End User

   Use:  Required

   XML Element:  <ServiceType>

   Description:  This defines the type of service over which the call is
      placed (similar to the Class of Service delivered with legacy
      emergency calls in some regions).  The implied mobility of this
      service cannot be relied upon.  A registry is created in
      Section 11.1.3.  The initial set of values is shown in Figure 5.
      More than one value MAY be returned.  For example, a VoIP inmate
      telephone service is a reasonable combination.

   Reason for Need:  Knowing the type of service can assist the PSAP in
      the handling of the call.

   How Used by Call Taker:  Call takers often use this information to
      determine what kinds of questions to ask callers and how much to
      rely on supportive information.  As the information is not always
      available, and the registry is not all encompassing, this is at
      best advisory information, but since it mimics a similar
      capability in some legacy emergency calling systems, it is known
      to be valuable.

      +--------------+------------------------------------------+
      | Name         | Description                              |
      +--------------+------------------------------------------+
      | wireless     | Wireless Telephone Service: Includes     |
      |              |   CDMA, GSM, Wi-Fi, WiMAX, and LTE       |
      |              |   (but not satellite)                    |
      |              |                                          |



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      | coin         | Fixed public pay/coin telephones: Any    |
      |              |   device operated by coin or credit card |
      |              |                                          |
      | one-way      | One-way outbound service                 |
      |              |                                          |
      | temp         | Soft dial tone/quick service/warm        |
      |              |   disconnect/suspended                   |
      |              |                                          |
      | MLTS-hosted  | Hosted multi-line telephone system       |
      |              |   such as Centrex                        |
      |              |                                          |
      | MLTS-local   | Local multi-line telephone system,       |
      |              |   including all PBXs, key systems, and   |
      |              |   Shared Tenant Services                 |
      |              |                                          |
      | sensor-      | These are devices that generate DATA     |
      |   unattended |   ONLY.  This is a one-way information   |
      |              |   transmit without interactive media.    |
      |              |                                          |
      | sensor-      | Devices that are supported by a          |
      |   attended   |   monitoring service provider or that    |
      |              |   are capable of supporting interactive  |
      |              |   media                                  |
      |              |                                          |
      | POTS         | Wireline: Plain Old Telephone Service    |
      |              |                                          |
      | OTT          | An over-the-top service that provides    |
      |              |   communication over arbitrary Internet  |
      |              |   access (fixed, nomadic, mobile)        |
      |              |                                          |
      | digital      | Wireline non-OTT digital phone service   |
      |              |                                          |
      | OPX          | Off-premise extension                    |
      |              |                                          |
      | relay        | A service where a human third-party      |
      |              |   agent provides additional assistance.  |
      |              |   This includes sign language relay/     |
      |              |   interpretation, telematics services    |
      |              |   that provide a human on the call,      |
      |              |   and similar services.                  |
      +--------------+------------------------------------------+

       Figure 5: Service Delivered by Provider to End User Registry

   The initial set of values has been collected from sources of
   currently used systems, including [NENA-02-010], [nc911], [NANP], and
   [LERG].




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4.2.3.  Service Mobility Environment

   Data Element:  Service Mobility Environment

   Use:  Required

   XML Element:  <ServiceMobility>

   Description:  This provides the service provider's view of the
      mobility of the caller's device.  As the service provider might
      not know the characteristics of the actual device or access
      network used, the value should be treated as advisory and not be
      relied upon.  A registry is created in Section 11.1.4 with the
      initial valid entries shown in Figure 6.

   Reason for Need:  Knowing the service provider's belief of mobility
      can assist the PSAP with the handling of the call.

   How Used by Call Taker:  To determine whether to assume the location
      of the caller might change.

                  +-----------+----------------------------+
                  | Token     | Description                |
                  +-----------+----------------------------+
                  | Mobile    | The device is able to move |
                  |           |   at any time              |
                  |           |                            |
                  | Fixed     | The device is not expected |
                  |           |   to move unless the       |
                  |           |   service is relocated     |
                  |           |                            |
                  | Nomadic   | The device is not expected |
                  |           |   to change its point of   |
                  |           |   attachment while on a    |
                  |           |   call                     |
                  |           |                            |
                  | Unknown   | No information is known    |
                  |           |   about the service        |
                  |           |   mobility environment for |
                  |           |   the device               |
                  +-----------+----------------------------+

                    Figure 6: Service Mobility Registry








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4.2.4.  EmergencyCallData.ServiceInfo Example

   <?xml version="1.0" encoding="UTF-8"?>
   <svc:EmergencyCallData.ServiceInfo
       xmlns:svc="urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo">
       <svc:DataProviderReference>2468.IBOC.MLTS.1359@example.org
       </svc:DataProviderReference>
       <svc:ServiceEnvironment>Business</svc:ServiceEnvironment>
       <svc:ServiceType>MLTS-hosted</svc:ServiceType>
       <svc:ServiceMobility>Fixed</svc:ServiceMobility>
   </svc:EmergencyCallData.ServiceInfo>

              Figure 7: EmergencyCallData.ServiceInfo Example

4.3.  Device Information

   This block provides information about the device used to place the
   call.  It SHOULD be provided by any service provider that knows what
   device is being used and by the device itself.  The MIME media type
   is 'application/EmergencyCallData.DeviceInfo+xml'.

4.3.1.  Device Classification

   Data Element:  Device Classification

   Use:  Optional

   XML Element:  <DeviceClassification>

   Description:  This data element defines the kind of device making the
      emergency call.  If the device provides the data structure, the
      device information SHOULD be provided.  If the service provider
      provides the structure and it knows what the device is, the
      service provider SHOULD provide the device information.  Often the
      carrier does not know what the device is.  It is possible to
      receive two Device Information blocks: one provided by the device
      and one from the service provider.  This information describes the
      device, not how it is being used.  This data element defines the
      kind of device making the emergency call.  A registry is created
      in Section 11.1.6 with the initial set of values as shown in
      Figure 8.

   Reason for Need:  The device classification implies the capability of
      the calling device and assists in identifying the meaning of the
      emergency call location information that is being presented.  For
      example, does the device require human intervention to initiate a
      call, or is this call the result of programmed instructions?  Does
      the calling device have the ability to update location or



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      condition changes?  Is this device interactive or a one-way
      reporting device?

   How Used by Call Taker:  Can provide the call taker context regarding
      the caller, the capabilities of the calling device, or the
      environment in which the device is being used and can assist in
      understanding the location information and capabilities of the
      calling device.  For example, a cordless handset might be outside
      or next door.

      +---------------+----------------------------------------+
      | Token         |  Description                           |
      +---------------+----------------------------------------+
      |cordless       | Cordless handset                       |
      |fixed          | Fixed phone                            |
      |satellite      | Satellite phone                        |
      |sensor-fixed   | Fixed (non-mobile) sensor/alarm device |
      |desktop        | Soft client on desktop PC              |
      |laptop         | Soft client on laptop-type device      |
      |tablet         | Soft client on tablet-type device      |
      |alarm-monitored| Alarm system                           |
      |sensor-mobile  | Mobile sensor device                   |
      |aircraft       | Aircraft telematics device             |
      |automobile     | Automobile/cycle/off-road telematics   |
      |truck          | Truck/construction telematics          |
      |farm           | Farm equipment telematics              |
      |marine         | Marine telematics                      |
      |personal       | Personal telematics device             |
      |feature-phone  | Cellular feature phone (not smartphone)|
      |smart-phone    | Cellular smartphone (native)           |
      |smart-phone-app| Soft client app on smartphone          |
      |unknown-device | Soft client on unknown device type     |
      |game           | Gaming console                         |
      |text-only      | Other text device                      |
      |NA             | Not Available                          |
      +---------------+----------------------------------------+

          Figure 8: Device Classification Registry Initial Values

4.3.2.  Device Manufacturer

   Data Element:  Device Manufacturer

   Use:  Optional

   XML Element:  <DeviceMfgr>





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   Description:  The plain language name of the manufacturer of the
      device.

   Reason for Need:  Used by PSAP management for post-mortem
      investigation/resolution.

   How Used by Call Taker:  Probably not used by the call taker but by
      PSAP management.

4.3.3.  Device Model Number

   Data Element:  Device Model Number

   Use:  Optional

   XML Element:  <DeviceModelNr>

   Description:  Model number of the device.

   Reason for Need:  Used by PSAP management for after-action
      investigation/resolution.

   How Used by Call Taker:  Probably not used by the call taker but by
      PSAP management.

4.3.4.  Unique Device Identifier

   Data Element:  Unique Device Identifier

   Use:  Optional

   XML Element:  <UniqueDeviceID>

   XML Attribute:  <TypeOfDeviceID>

   Description:  A string that identifies the specific device (or the
      device's current Subscriber Identification Module (SIM)) making
      the call or creating an event.  Note that more than one
      <UniqueDeviceID> can be present to supply more than one of the
      identifying values.

      The <TypeOfDeviceID> attribute identifies the type of device
      identifier.  A registry is created in Section 11.1.7 with an
      initial set of values shown in Figure 9.







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   Reason for Need:  Uniquely identifies the device (or, in the case of
      International Mobile Subscriber Identity (IMSI), a SIM),
      independent of any signaling identifiers present in the call
      signaling stream.

   How Used by Call Taker:  Probably not used by the call taker; might
      be used by PSAP management during an investigation.  (For example,
      if a PSAP experiences repeated false/accidental calls and there is
      no callback number or it isn't usable, the PSAP might need to try
      to track down the device using various means, e.g., contacting
      service providers in the area.)  In the case of handsets without
      current service, it might be possible to determine who last had
      service.  Another example might be a disconnected call where the
      call taker believes there is a need for assistance but was not
      able to obtain a location or other information.

   Example:  <UniqueDeviceID TypeOfDeviceID="SN">12345</UniqueDeviceID>

      +--------+------------------------------------------+
      | Token  | Description                              |
      +--------+------------------------------------------+
      | MEID   | Mobile Equipment Identifier  (CDMA)      |
      | ESN    | Electronic Serial Number (GSM)           |
      | MAC    | Media Access Control Address (IEEE)      |
      | WiMAX  | Device Certificate Unique ID             |
      | IMEI   | International Mobile Equipment ID (GSM)  |
      | IMSI   | International Mobile Subscriber ID (GSM) |
      | UDI    | Unique Device Identifier                 |
      | RFID   | Radio Frequency Identification           |
      | SN     | Manufacturer Serial Number               |
      +--------+------------------------------------------+

               Figure 9: Registry of Device Identifier Types

4.3.5.  Device/Service-Specific Additional Data Structure

   Data Element:  Device/service-specific additional data structure

   Use:  Optional

   XML Element:  <DeviceSpecificData>

   Description:  A URI representing additional data whose schema is
      specific to the device or service that created it.  (For example,
      a medical device or medical device monitoring service might have a
      defined set of medical data.)  The URI, when dereferenced, MUST
      yield a data structure defined by the device/service-specific




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      additional data type value.  Different data can be created by each
      classification, e.g., a data set created by a medical device.

   Reason for Need:  Provides device/service-specific data that can be
      used by the call taker and/or responders.

   How Used by Call Taker:  Provide information to guide call takers to
      select appropriate responders, give appropriate pre-arrival
      instructions to callers, and advise responders of what to be
      prepared for.  May be used by responders to guide assistance
      provided.

4.3.6.  Device/Service-Specific Additional Data Structure Type

   Data Element:  Type of device/service-specific additional data
      structure

   Use:  Conditional.  MUST be provided when a device/service-specific
      additional data URI is provided.

   XML Element:  <DeviceSpecificType>

   Description:  A value from the registry defined in Section 11.1.8 to
      describe the type of data located at the device/service-specific
      additional data structure.  The initial values shown in Figure 10
      currently only include IEEE 1512, which is the United States
      Department of Transportation (USDoT) model for traffic incidents.

   Reason for Need:  This data element allows identification of
      externally defined schemas, which might have additional data that
      can assist in emergency response.

   How Used by Call Taker:  This data element allows the end user (call
      taker or first responder) to know what type of additional data is
      available to aid in providing the needed emergency services.

   Note:  This mechanism is not appropriate for information specific to
      a location or a caller (person).

   +---------+---------------------------+--------------------------+
   |  Token  |       Description         |       Specification      |
   +---------+---------------------------+--------------------------+
   |IEEE1512 |Common Incident Management |       IEEE 1512-2006     |
   |         |  Message Set (USDoT model |                          |
   |         |  for traffic incidents)   |                          |
   +---------+---------------------------+--------------------------+

               Figure 10: Device/Service Data Type Registry



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   The IEEE 1512-2006 specifications can be found at [IEEE-1512-2006].

4.3.7.  EmergencyCallData.DeviceInfo Example

   <?xml version="1.0" encoding="UTF-8"?>
   <dev:EmergencyCallData.DeviceInfo
       xmlns:dev="urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo">
       <dev:DataProviderReference>d4b3072df.201409182208075@example.org
       </dev:DataProviderReference>
       <dev:DeviceClassification>fixed</dev:DeviceClassification>
       <dev:DeviceMfgr>Nokia</dev:DeviceMfgr>
       <dev:DeviceModelNr>Lumia 800</dev:DeviceModelNr>
       <dev:UniqueDeviceID TypeOfDeviceID="IMEI">35788104
       </dev:UniqueDeviceID>
   </dev:EmergencyCallData.DeviceInfo>

              Figure 11: EmergencyCallData.DeviceInfo Example

4.4.  Owner/Subscriber Information

   This block describes the owner of the device (if provided by the
   device) or the subscriber information (if provided by a service
   provider).  The contact location is not necessarily the location of
   the caller or incident but is rather the nominal contact address.
   The MIME media type is 'application/
   EmergencyCallData.SubscriberInfo+xml'.

   In some jurisdictions, some or all parts of the subscriber-specific
   information are subject to privacy constraints.  These constraints
   vary but dictate which information can be displayed and logged.  A
   general privacy indicator expressing a desire for privacy by the
   subscriber is provided.  The interpretation of how this is applied is
   left to the receiving jurisdiction as the custodians of the local
   regulatory requirements.  This matches an equivalent privacy flag
   provided in some legacy emergency call systems.

4.4.1.  Subscriber Data Privacy Indicator

   Attribute:  'privacyRequested', Boolean.

   Use:  Conditional.  This attribute MUST be provided if the owner/
      subscriber information block is not empty.

   Description:  The subscriber data privacy indicator specifically
      expresses the subscriber's desire for privacy.  In some
      jurisdictions, subscriber services can have a specific "Type of
      Service" that prohibits information, such as the name of the
      subscriber, from being displayed.  This attribute is provided to



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      explicitly indicate whether the subscriber service includes such
      constraints.  The interpretation of this indicator is left to each
      jurisdiction (in keeping with the semantics of the privacy
      indicator provided in some legacy emergency call systems).
      Because the interpretation of this indicator varies based on local
      regulations, this document cannot describe the exact semantics nor
      indicate which fields are affected (the application of this
      indicator might affect the display of data contained in any of the
      blocks).

   Reason for Need:  Some jurisdictions require subscriber privacy to be
      observed when processing emergency calls.

   How Used by Call Taker:  Where privacy is indicated, the call taker
      might not have access to some aspects of the subscriber
      information.

4.4.2.  xCard for Subscriber's Data

   Data Element:  xCard for Subscriber's Data

   Use:  Conditional.  Subscriber data MUST be provided unless it is not
      available.  Some services, such as prepaid phones, non-initialized
      phones, etc., do not have information about the subscriber.

   XML Element:  <SubscriberData>

   Description:  Information known by the service provider or device
      about the subscriber, e.g., Name, Address, Individual Telephone
      Number, Main Telephone Number, and any other data.  <n>, <org> (if
      appropriate), <adr>, <tel>, and <email> are suggested at a
      minimum.  If more than one <tel> property is provided, a parameter
      from the "vCard Property Values" registry MUST be specified on
      each <tel>.  While some data (such as <anniversary>) might not
      seem obviously relevant for emergency services, any data is
      potentially useful in some emergency circumstances.

   Reason for Need:  When the caller is unable to provide information,
      this data can be used to obtain it.

   How Used by Call Taker:  Obtaining critical information about the
      caller and possibly the location when it is not able to be
      obtained otherwise.  While the location here is not necessarily
      that of a caller, in some circumstances it can be helpful in
      locating the caller when other means have failed.






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4.4.3.  EmergencyCallData.SubscriberInfo Example

   <?xml version="1.0" encoding="UTF-8"?>
   <sub:EmergencyCallData.SubscriberInfo
        xmlns:sub=
            "urn:ietf:params:xml:ns:EmergencyCallData:SubscriberInfo"
        privacyRequested="false">
       <sub:DataProviderReference>FEABFECD901@example.org
       </sub:DataProviderReference>
       <sub:SubscriberData xmlns="urn:ietf:params:xml:ns:vcard-4.0">
            <vcard>
                   <fn><text>Simon Perreault</text></fn>
                   <n>
                       <surname>Perreault</surname>
                       <given>Simon</given>
                       <additional/>
                       <prefix/>
                       <suffix>ing. jr</suffix>
                       <suffix>M.Sc.</suffix>
                   </n>
                   <bday><date>--0203</date></bday>
                   <anniversary>
                       <date-time>20090808T1430-0500</date-time>
                   </anniversary>
                   <gender><sex>M</sex></gender>
                   <lang>
                       <parameters><pref><integer>1</integer></pref>
                       </parameters>
                       <language-tag>fr</language-tag>
                   </lang>
                   <lang>
                       <parameters><pref><integer>2</integer></pref>
                       </parameters>
                       <language-tag>en</language-tag>
                   </lang>
                   <org>
                       <parameters><type><text>work</text></type>
                       </parameters>
                       <text>Viagenie</text>
                   </org>
                   <adr>
                       <parameters>
                           <type><text>work</text></type>
                           <label><text>Simon Perreault
                               2875 boul. Laurier, suite D2-630
                               Quebec, QC, Canada
                               G1V 2M2</text></label>
                       </parameters>



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                       <pobox/>
                       <ext/>
                       <street>2875 boul. Laurier,
                               suite D2-630</street>
                       <locality>Quebec</locality>
                       <region>QC</region>
                       <code>G1V 2M2</code>
                       <country>Canada</country>
                   </adr>
                   <tel>
                       <parameters>
                           <type>
                               <text>work</text>
                               <text>voice</text>
                           </type>
                       </parameters>
                       <uri>tel:+1-418-656-9254;ext=102</uri>
                   </tel>
                   <tel>
                       <parameters>
                           <type>
                               <text>work</text>
                               <text>voice</text>
                               <text>main-number</text>
                           </type>
                       </parameters>
                       <uri>tel:+1-418-555-0000</uri>
                   </tel>
                   <tel>
                       <parameters>
                           <type>
                               <text>work</text>
                               <text>text</text>
                               <text>voice</text>
                               <text>cell</text>
                               <text>video</text>
                           </type>
                       </parameters>
                       <uri>tel:+1-418-262-6501</uri>
                   </tel>
                   <email>
                       <parameters><type><text>work</text></type>
                       </parameters>
                       <text>simon.perreault@viagenie.ca</text>
                   </email>
                   <geo>
                       <parameters><type><text>work</text></type>
                       </parameters>



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                       <uri>geo:46.766336,-71.28955</uri>
                   </geo>
                   <key>
                       <parameters><type><text>work</text></type>
                       </parameters>
                       <uri>
                       http://www.viagenie.ca/simon.perreault/simon.asc
                       </uri>
                   </key>
                   <tz><text>America/Montreal</text></tz>
                   <url>
                       <parameters><type><text>home</text></type>
                       </parameters>
                       <uri>http://nomis80.org</uri>
                   </url>
           </vcard>
       </sub:SubscriberData>
   </sub:EmergencyCallData.SubscriberInfo>

            Figure 12: EmergencyCallData.SubscriberInfo Example

4.5.  Comment

   This block provides a mechanism for the data provider to supply
   extra, human-readable information to the PSAP.  It is not intended
   for a general purpose extension mechanism nor does it aim to provide
   machine-readable content.  The MIME media type is 'application/
   EmergencyCallData.Comment+xml'.

4.5.1.  Comment

   Data Element:  EmergencyCallData.Comment

   Use:  Optional

   XML Element:  <Comment>

   Description:  Human-readable text providing additional information to
      the PSAP staff.

   Reason for Need:  Explanatory information for values in the data
      structure.

   How Used by Call Taker:  To interpret the data provided.







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4.5.2.  EmergencyCallData.Comment Example

   <?xml version="1.0" encoding="UTF-8"?>
   <com:EmergencyCallData.Comment
        xmlns:com="urn:ietf:params:xml:ns:EmergencyCallData:Comment">
      <com:DataProviderReference>string0987654321@example.org
      </com:DataProviderReference>
      <com:Comment xml:lang="en">This is an example text.</com:Comment>
   </com:EmergencyCallData.Comment>

               Figure 13: EmergencyCallData.Comment Example

5.  Issues with Getting New Types of Data into Use

   This document describes two mechanisms that allow extension of the
   kind of data provided with an emergency call: define a new block or
   define a new device/service-specific additional data URL for the
   DeviceInfo block (Section 4.3.5).  While defining new data types and
   getting a new device or application to send the new data might be
   easy, getting PSAPs and responders to actually retrieve the data and
   use it will be difficult.  New mechanism providers should understand
   that acquiring and using new forms of data usually require software
   upgrades at the PSAP and/or responders, as well as training of call
   takers and responders in how to interpret and use the information.
   Legal and operational review might also be needed.  Overwhelming a
   call taker or responder with too much information is highly
   discouraged.  Thus, the barrier to supporting new data is quite high.

   The mechanisms this document describes are meant to encourage
   development of widely supported, common data formats for classes of
   devices.  If all manufacturers of a class of device use the same
   format, and the data can be shown to improve outcomes, then PSAPs and
   responders can be encouraged to upgrade their systems and train their
   staff to use the data.  Variations, however well intentioned, are
   unlikely to be supported.

   Implementors should consider that data from sensor-based devices in
   some cases might not be useful to call takers or PSAPs (and privacy,
   liability, or other considerations might preclude the PSAP from
   accessing or handling the data) but might be of use to responders.
   Each data item provided with the call in conformance with this
   document can be accessed by responders or other entities in the
   emergency services, whether or not the data is accessed by the PSAP.








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5.1.  Choosing between Defining a New Type of Block or a New Type of
      Device/Service-Specific Additional Data

   For devices that have device- or service-specific data, there are two
   choices to carry it.  A new block can be defined, or the device/
   service-specific additional data URL in the DeviceInfo block can be
   used and a new type defined for it.  The data passed would likely be
   the same in either case.  Considerations for choosing the mechanism
   under which to register include:

   Applicability:  Information that will be supported by many kinds of
      devices or services are more appropriately defined as separate
      blocks.

   Privacy:  Information sent as a device/service-specific additional
      data URL in the DeviceInfo block is by reference (not by value),
      which inherently provides some additional privacy protection
      (since the requester needs to supply a certificate which is
      verified by the supplier).

   Size:  Information that can be very large might be better sent in the
      DeviceInfo block, rather than in a new block, so that
      implementations are unable to send the data by value.  Conversely,
      data that is small might best be sent in a separate block so that
      it can be sent by value.

   Availability of a server:  Providing the data via the DeviceInfo
      block requires that a server be available from which to retrieve
      the data.  Providing the data via a new block allows it to be sent
      by value.

6.  Data Transport Mechanisms

   This section defines how to convey additional data to an emergency
   service provider.  Two different means are specified: the first uses
   call signaling; the second uses the <provided-by> element of a PIDF-
   LO [RFC4119].

   1.  First, the ability to embed a Uniform Resource Identifier (URI)
       in an existing SIP header field, the Call-Info header field, is
       defined.  The URI points to the additional data structure.  The
       Call-Info header field is specified in Section 20.9 of [RFC3261].

       This document adds a new compound token starting with the value
       'EmergencyCallData' for the Call-Info 'purpose' parameter.  If
       the 'purpose' parameter is set to a value starting with
       'EmergencyCallData', then the Call-Info header field contains
       either an HTTPS URL pointing to an external resource or a Content



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       Indirection (CID) URI that allows the data structure to be placed
       in the body of the SIP message.  The 'purpose' parameter also
       indicates the kind of data (by its MIME media subtype) that is
       available at the URI.

       As the data is conveyed using a URI in the SIP signaling, the
       data itself can reside on an external resource or can be
       contained within the body of the SIP message.  When the URI
       refers to data at an external resource, the data is said to be
       passed by reference.  When the URI refers to data contained
       within the body of the SIP message, the data is said to be passed
       by value.  A PSAP or emergency responder is able to examine the
       type of data provided and selectively access the data it is
       interested in, while forwarding all of it (the values or
       references) to downstream entities.

       To be conveyed in a SIP body, additional data about a call is
       defined as a series of MIME objects (also referred to as a
       "block" of data).  Each block defined in this document is an XML
       data structure identified by its MIME media type.  (Blocks
       defined by others can be encoded in XML or not, as identified by
       their MIME registration.)  As usual, whenever more than one MIME
       part is included in the body of a message, MIME multipart (i.e.,
       'multipart/mixed') encloses them all.

       This document defines a set of XML schemas and MIME media types
       used for each block defined here.  When additional data is passed
       by value in the SIP signaling, each CID URL points to one block
       in the body.  Multiple URIs are used within a Call-Info header
       field (or multiple Call-Info header fields) to point to multiple
       blocks.  When additional data is provided by reference (in SIP
       signaling or the <provided-by> element of a PIDF-LO), each HTTPS
       URL references one block; the data is retrieved with an HTTPS GET
       operation, which returns the block as an object (the blocks
       defined here are returned as XML objects).

   2.  Second, the ability to embed additional data structures in the
       <provided-by> element of a PIDF-LO [RFC4119] is defined.

       In addition to service providers in the call path, the access
       network provider generally has similar information that can be
       valuable to the PSAP.  When the access network provider and
       service provider are separate entities, the access network does
       not participate in the application-layer signaling (and hence
       cannot add a Call-Info header field to the SIP message) but can
       provide location information in a PIDF-LO.  When the access
       network provider supplies location information in the form of a
       PIDF-LO from a location server via a location configuration



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       protocol, it has the ability to add the data structures defined
       in this document (or references to them) within the PIDF-LO.

       The data in these data structures is not specific to the location
       itself, but rather provides descriptive information having to do
       with the immediate circumstances about the provider's provision
       of the location (e.g., the identity of the access network
       provider, how to contact that entity, what kind of service the
       access network provides, subscriber information, etc.).  This
       data is similar in nearly every respect to the data known by
       service providers in the path of the call.  The <provided-by>
       element of the PIDF-LO is a mechanism for the access network
       provider to supply the information.  This document describes a
       namespace per [RFC4119] for inclusion in the <provided-by>
       element of a PIDF-LO for adding information known to the access
       network provider.  The access network provider SHOULD provide
       additional data within a <provided-by> element of a PIDF-LO it
       returns for emergency use (e.g., if requested with an HTTP-
       Enabled Location Delivery (HELD) 'responseTime' attribute of
       'emergencyRouting' or 'emergencyDispatch' [RFC5985]).

   One or more blocks of data registered in the "Emergency Call
   Additional Data" registry, as defined in Section 11.1.9, can be
   included or referenced in the SIP signaling (using the Call-Info
   header field) or in the <provided-by> element of a PIDF-LO.  For
   interoperability, only blocks in the registry are permitted to be
   sent using the mechanisms specified in this document.  Since multiple
   entities are expected to provide sets of data, the data itself needs
   information describing the source.  Consequently, each entity adding
   additional data MUST supply a 'Data Provider' block.  All other
   blocks are optional, but each entity SHOULD supply all blocks where
   it has at least some of the information in the block.

   Note that, as with any mechanism, failures are possible.  For
   example, a block (provided by value or by reference) might not be the
   type indicated by the 'purpose' parameter, or might be badly formed,
   etc.  The general principle that applies to emergency calls is that
   it is more important for the call to go through than for everything
   to be correct.  Thus, most PSAPs will process a call if at all
   possible, even if data is missing or other failures occur.











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6.1.  Transmitting Blocks Using Call-Info

   A URI to a block MAY be inserted in any SIP request or response
   method (most often INVITE or MESSAGE), using a Call-Info header field
   containing a 'purpose' value starting with 'EmergencyCallData', a dot
   ('.'), and the type of data available at the URI.  The type of data
   is denoted by including the root of the MIME media subtype (the
   'EmergencyCallData' prefix is not repeated), omitting any suffix such
   as '+xml'.  For example, when referencing a block with MIME media
   type 'application/EmergencyCallData.ProviderInfo+xml', the 'purpose'
   parameter is set to 'EmergencyCallData.ProviderInfo'.  An example
   Call-Info header field for this would be:

   Call-Info:  https://www.example.com/23sedde3;
       purpose="EmergencyCallData.ProviderInfo"

   A Call-Info header field with a 'purpose' value starting with
   'EmergencyCallData' only has meaning in the context of an emergency
   call (as ascertained by the presence of an emergency service URN in a
   Request-URI header field of a SIP message), test emergency calls
   (using an appropriate service URN), and some private-use calls where
   the endpoints have a preexisting relationship and privacy concerns do
   not apply because of the relationship; use in other contexts is
   undefined and is likely to unnecessarily expose confidential data.

   If the data is provided by reference, an HTTPS URI MUST be included,
   and consequently, Transport Layer Security (TLS) protection is used
   during the retrieval of the information.

   The data can also be supplied by value in any SIP request or response
   method that is permitted to contain a body (i.e., not a BYE request)
   [RFC3261].  In this case, CID [RFC2392] is used, with the CID URL
   referencing the MIME body part containing the data.  Note that
   [RFC3261] forbids proxies from altering message bodies, so entities
   in the call path that add blocks by value need to do so using an
   appropriate SIP entity (e.g., a back-to-back user agent).

   Transmitting data by value is especially useful in certain cases,
   such as when the data exists in or is generated by the originating
   device but is not intended for very large data blocks.  Additional
   security and privacy considerations apply to data transmitted by
   value, as discussed in Sections 9 and 10, respectively.

   More than one Call-Info header field with a 'purpose' value starting
   with 'EmergencyCallData' can be expected, but at least one MUST be
   provided.  The device MUST provide one unless it knows that a service
   provider is in the path of the call.  The device MAY insert one if it
   uses a service provider.  Each service provider in the path of an



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   emergency call MUST insert its own.  For example, a device, a
   telematics service provider in the call path, as well as the mobile
   carrier handling the call will each provide one.  There might be
   circumstances where there is a service provider who is unaware that
   the call is an emergency call and cannot reasonably be expected to
   determine that it is an emergency call.  In that case, that service
   provider is not expected to provide EmergencyCallData.

   When blocks are transmitted by value, the 'purpose' parameter in a
   Call-Info header field identifies the data, and the CID URL points to
   the data block in the body (which has a matching Content-ID body part
   header field).  When a data block is carried in a signed or encrypted
   body part, the enclosing multipart (e.g., 'multipart/signed' or
   'multipart/encrypted') has the same Content-ID as the data part.
   This allows an entity to identify and access the data blocks it is
   interested in without having to dive deeply into the message
   structure or decrypt parts it is not interested in.

6.2.  Transmitting Blocks by Reference Using the <provided-by> Element

   The <EmergencyCallDataReference> element is used to transmit an
   additional data block by reference within a <provided-by> element of
   a PIDF-LO.  The <EmergencyCallDataReference> element has two
   attributes: 'ref' to specify the URL and 'purpose' to indicate the
   type of data block referenced.  The value of 'ref' is an HTTPS URL
   that resolves to a data structure with information about the call.
   The value of 'purpose' is the same as used in a Call-Info header
   field (as specified in Section 6.1).

   For example, to reference a block with MIME media type 'application/
   EmergencyCallData.ProviderInfo+xml', the 'purpose' parameter is set
   to 'EmergencyCallData.ProviderInfo'.  An example
   <EmergencyCallDataReference> element for this would be:

      <EmergencyCallDataReference ref="https://www.example.com/23sedde3"
      purpose="EmergencyCallData.ProviderInfo"/>

   The <EmergencyCallDataReference> element transmits one data block;
   multiple data blocks are transmitted by using multiple
   <EmergencyCallDataReference> elements.  Multiple
   <EmergencyCallDataReference> elements MAY be included as child
   elements inside the <provided-by> element.









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   The following is a simplified example:

   <provided-by>
           <EmergencyCallDataReference
                    purpose="EmergencyCallData.ServiceInfo"
                    ref="https://example.com/ref2" />

           <EmergencyCallDataReference
                    purpose="EmergencyCallData.ProviderInfo"
                    ref="https://example.com/ref3" />

           <EmergencyCallDataReference
                    purpose="EmergencyCallData.Comment"
                    ref="https://example.com/ref4" />
   </provided-by>

                    Example <provided-by> by Reference

   For an example in context, Figure 18 shows a PIDF-LO example with an
   <EmergencyCallDataReference> element pointing to an
   EmergencyCallData.ServiceInfo data block with the URL in the 'ref'
   attribute and the 'purpose' attribute set to
   'EmergencyCallData.ServiceInfo'.

6.3.  Transmitting Blocks by Value Using the <provided-by> Element

   It is RECOMMENDED that access networks supply the data specified in
   this document by reference, because PIDF-LOs can be fetched by a
   client or other entity and stored locally, so providing the data by
   value risks exposing private information to a larger audience.

   The <EmergencyCallDataValue> element is used to transmit one or more
   additional data blocks by value within a <provided-by> element of a
   PIDF-LO.  Each block being transmitted is placed (as a child element)
   inside the <EmergencyCallDataValue> element.  (The same XML structure
   as would be contained in the corresponding MIME media type body part
   is placed inside the <EmergencyCallDataValue> element.)  Multiple
   <EmergencyCallDataValue> elements MAY be included as child elements
   in the <provided-by> element.












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   The following is a simplified example:

   <provided-by>

           <EmergencyCallDataValue>

             <EmergencyCallData.ProviderInfo
                xmlns=
                "urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo">
                <DataProviderReference>flurbit735@es.example.com
                  </DataProviderReference>
                <DataProviderString>Access Network Examples, Inc.
                  </DataProviderString>
                <ProviderID>urn:nena:companyid:Test</ProviderID>
                <ProviderIDSeries>NENA</ProviderIDSeries>
                <TypeOfProvider>Access Network Provider
                  </TypeOfProvider>
                <ContactURI>tel:+1-555-555-0897</ContactURI>
                <Language>en</Language>
              </EmergencyCallData.ProviderInfo>

              <EmergencyCallData.Comment
                 xmlns=
                 "urn:ietf:params:xml:ns:EmergencyCallData:Comment">
                 <DataProviderReference>flurbit735@es.example.com
                   </DataProviderReference>
                 <Comment xml:lang="en">This is an example text.
                   </Comment>
              </EmergencyCallData.Comment>

           </EmergencyCallDataValue>

   </provided-by>

                      Example <provided-by> by Value

   For an example in context, Figure 18 shows a PIDF-LO example that
   contains a <provided-by> element with the
   <EmergencyCallData.ProviderInfo> and the <EmergencyCallData.Comment>
   elements as child elements of an <EmergencyCallDataValue> element.

6.4.  The Content-Disposition Parameter

   RFC 5621 [RFC5621] discusses the handling of message bodies in SIP.
   It updates and clarifies handling originally defined in RFC 3261
   [RFC3261] based on implementation experience.  While RFC 3261 did not
   mandate support for 'multipart' message bodies, 'multipart/mixed'
   MIME bodies are used by many extensions (including this document)



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   today.  For example, adding a PIDF-LO, a Session Description Protocol
   (SDP), and additional data in the body of a SIP message requires a
   'multipart' message body.

   RFC 3204 [RFC3204] and RFC 3459 [RFC3459] define the 'handling'
   parameter for the Content-Disposition header field.  These RFCs
   describe how a User Agent Server (UAS) reacts if it receives a
   message body whose content type or disposition type it does not
   understand.  If the 'handling' parameter has the value 'optional',
   the UAS ignores the message body.  If the 'handling' parameter has
   the value 'required', the UAS returns a 415 (Unsupported Media Type)
   response.  The 'by-reference' disposition type of RFC 5621 [RFC5621]
   allows a SIP message to contain a reference to the body part, and the
   SIP User Agent (UA) processes the body part according to the
   reference.  This is the case for a Call-Info header field containing
   a CID URL.

   As an example, a SIP message indicates the 'Content-Disposition'
   parameter in the body of the SIP message as shown in Figure 14.

         Content-Type: application/sdp
         ...Omit Content-Disposition here; defaults are ok

         ...SDP goes in here

         --boundary1
         Content-Type: application/pidf+xml
         Content-ID: <target123@atlanta.example.com>
         Content-Disposition: by-reference;handling=optional

         ...PIDF-LO goes in here

         --boundary1
         Content-Type: application/EmergencyCallData.ProviderInfo+xml
         Content-ID: <1234567890@atlanta.example.com>
         Content-Disposition: by-reference; handling=optional

         ...Data provider information data goes in here

         --boundary1--

      Figure 14: Example for Use of the Content-Disposition Parameter
                                  in SIP








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7.  Examples

   This section illustrates a longer and more complex example, as shown
   in Figure 15.  In this example, additional data is added by the end
   device, included by the VoIP provider, and provided by the access
   network provider (via the PIDF-LO).

     O   +----+      [============]                     [=============]
    /|\  | UA |      [  Access    ]                     [ VoIP        ]
     |   +----+      [  Network   ]                     [ Provider    ]
    / \              [  Provider  ]                     [ example.org ]
                     [            ]                     [             ]
    (1)              [            ] (2)                 [             ]
    Emergency Call   [            ] Emergency Call      [             ]
    ------------------------------------------------------>           ]
    +Device Info     [            ] +Device Info        [             ]
    +Data Prov. Info [       ^    ] +Data Provider Info [    |        ]
    +Location URI    [=======.====] +Location URI       [====|========]
                             .                               |
                             .                               |
      +Location              .      [==============]         |
      +Owner/Subscriber Info .      [              ]   (3)   |
      +Device Info           .  (4) [           <------------+
      +Data Provider Info #3 ..........>           ] Emergency Call
                                    [              ] +Device Info
                                    [     PSAP     ] +Data Prov. Info #2
                                    [              ] +Location URI
                                    [==============]


     Legend:

         --- Emergency Call Setup Procedure
         ... Location Retrieval/Response

                  Figure 15: Additional Data Example Flow















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   The example scenario starts with the end device itself adding device
   information, owner/subscriber information, a location URI, and data
   provider information to the outgoing emergency call setup message
   (see step #1 in Figure 15).  The SIP INVITE example is shown in
   Figure 16.

      INVITE urn:service:sos SIP/2.0
      Via: SIPS/2.0/TLS server.example.com;branch=z9hG4bK74bf9
      Max-Forwards: 70
      To: <urn:service:sos>
      From: Hannes Tschofenig <sips:hannes@example.com>;tag=9fxced76sl
      Call-ID: 3848276298220188511@example.com
      Call-Info: <http://wwww.example.com/hannes/photo.jpg>
                     ;purpose=icon,
        <http://www.example.com/hannes/> ;purpose=info,
        <cid:1234567890@atlanta.example.com>
            ;purpose=EmergencyCallData.ProviderInfo,
        <cid:0123456789@atlanta.example.com>
            ;purpose=EmergencyCallData.DeviceInfo
      Geolocation: <https://ls.example.net:9768/357yc6s64ceyoiuy5ax3o>
      Geolocation-Routing: yes
      Accept: application/sdp, application/pidf+xml,
         application/EmergencyCallData.ProviderInfo+xml
      CSeq: 31862 INVITE
      Contact: <sips:hannes@example.com>
      Content-Type: multipart/mixed; boundary=boundary1
      Content-Length: ...

      --boundary1
      Content-Type: application/sdp

      ...SDP goes here

      --boundary1
      Content-Type: application/EmergencyCallData.DeviceInfo+xml
      Content-ID: <0123456789@atlanta.example.com>
      Content-Disposition: by-reference;handling=optional

      <?xml version="1.0" encoding="UTF-8"?>
      <dev:EmergencyCallData.DeviceInfo
           xmlns:dev=
           "urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo">
          <dev:DataProviderReference>
               d4b3072df09876543@[93.184.216.119]
               </dev:DataProviderReference>
          <dev:DeviceClassification>laptop</dev:DeviceClassification>
          <dev:UniqueDeviceID
               TypeOfDeviceID="MAC">00-0d-4b-30-72-df



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               </dev:UniqueDeviceID>
      </dev:EmergencyCallData.DeviceInfo>

      --boundary1
      Content-Type: application/EmergencyCallData.ProviderInfo+xml
      Content-ID: <1234567890@atlanta.example.com>
      Content-Disposition: by-reference;handling=optional

      <?xml version="1.0" encoding="UTF-8"?>
      <pi:EmergencyCallData.ProviderInfo
         xmlns:pi=
            "urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo">
      <pi:DataProviderReference>d4b3072df09876543@[93.184.216.119]
         </pi:DataProviderReference>
      <pi:DataProviderString>Hannes Tschofenig</pi:DataProviderString>
      <pi:TypeOfProvider>Client</pi:TypeOfProvider>
      <pi:ContactURI>tel:+1-555-555-0123</pi:ContactURI>
      <pi:Language>en</pi:Language>
      <pi:DataProviderContact
         xmlns="urn:ietf:params:xml:ns:vcard-4.0">
         <vcard>
            <fn><text>Hannes Tschofenig</text></fn>
            <n>
               <surname>Hannes</surname>
               <given>Tschofenig</given>
               <additional/>
               <prefix/>
               <suffix>Dipl. Ing.</suffix>
            </n>
            <bday><date>--0203</date></bday>
            <anniversary>
               <date-time>20090808T1430-0500</date-time>
            </anniversary>
            <gender><sex>M</sex></gender>
            <lang>
                <parameters><pref><integer>1</integer></pref>
                </parameters>
                <language-tag>de</language-tag>
            </lang>
            <lang>
               <parameters><pref><integer>2</integer></pref>
               </parameters>
               <language-tag>en</language-tag>
            </lang>
            <adr>
               <parameters>
                  <type><text>work</text></type>
                  <label><text>Hannes Tschofenig



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                     Linnoitustie 6
                     Espoo, Finland
                     02600</text></label>
               </parameters>
               <pobox/>
               <ext/>
               <street>Linnoitustie 6</street>
               <locality>Espoo</locality>
               <region>Uusimaa</region>
               <code>02600</code>
               <country>Finland</country>
            </adr>
            <adr>
               <parameters>
                  <type><text>home</text></type>
                  <label><text>Hannes Tschofenig
                     c/o Hotel DuPont
                     42 W 11th St
                     Wilmington, DE 19801
                     USA</text></label>
               </parameters>
               <pobox/>
               <ext/>
               <street>42 W 11th St</street>
                  <locality>Wilmington</locality>
                  <region>DE</region>
                  <code>19801</code>
                  <country>USA</country>
            </adr>
            <tel>
               <parameters>
                  <type>
                     <text>work</text>
                     <text>voice</text>
                  </type>
               </parameters>
               <uri>tel:+358 50 4871445</uri>
            </tel>
            <tel>
               <parameters>
                  <type>
                     <text>home</text>
                     <text>voice</text>
                  </type>
               </parameters>
               <uri>tel:+1-555-555-0123</uri>
            </tel>
            <tel>



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               <parameters>
                  <type>
                     <text>work</text>
                     <text>voice</text>
                     <text>main-number</text>
                  </type>
               </parameters>
               <uri>tel:+1-302-594-3100</uri>
            </tel>
            <email>
               <parameters><type><text>work</text></type>
               </parameters>
               <text>hannes.tschofenig@nsn.com</text>
            </email>
            <geo>
               <parameters><type><text>work</text></type>
               </parameters>
               <uri>geo:60.210796,24.812924</uri>
            </geo>
            <geo>
               <parameters><type><text>home</text></type>
               </parameters>
               <uri>geo:39.746537,-75.548027</uri>
            </geo>
            <key>
               <parameters>
                  <type><text>home</text></type>
               </parameters>
               <uri>https://www.example.com/key.asc</uri>
            </key>
            <tz><text>Finland/Helsinki</text></tz>
            <url>
               <parameters><type><text>home</text></type>
               </parameters>
               <uri>http://example.com/hannes.tschofenig
               </uri>
            </url>
         </vcard>
      </pi:DataProviderContact>
      </pi:EmergencyCallData.ProviderInfo>
      --boundary1--

       Figure 16: End Device Sending SIP INVITE with Additional Data

   In this example, information available to the access network provider
   is included in the call setup message only indirectly via the use of
   the location reference.  The PSAP has to retrieve it via a separate
   lookup step.  Since the access network provider and the VoIP service



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   provider are two independent entities in this scenario, the access
   network provider is not involved in application-layer exchanges; the
   SIP INVITE transits the access network transparently, as illustrated
   in steps #1 and #2 (the access network does not alter the SIP
   INVITE).

   The VoIP service provider receives the message and determines, based
   on the service URN, that the incoming request is an emergency call.
   It performs typical emergency-services-related tasks (such as
   location-based routing) and adds additional data, namely service and
   subscriber information as well as data provider information #2, to
   the outgoing message.  For the example, we assume a VoIP service
   provider deploys a back-to-back user agent allowing additional data
   to be included in the body of the SIP message (rather than by
   reference), which allows us to illustrate the use of multiple data
   provider info blocks.  The resulting message is shown in Figure 17.
   The SIP INVITE is sent to the PSAP in step #3.

      INVITE sips:psap@example.org SIP/2.0
      Via: SIPS/2.0/TLS server.example.com;branch=z9hG4bK74bf9
      Max-Forwards: 70
      To: <urn:service:sos>
      From: Hannes Tschofenig <sips:hannes@example.com>;tag=9fxced76sl
      Call-ID: 3848276298220188511@example.com
      Call-Info: <http://wwww.example.com/hannes/photo.jpg>;
         purpose=icon,
         <http://www.example.com/hannes/>; purpose=info,
         <cid:1234567890@atlanta.example.com>;
         purpose=EmergencyCallData.ProviderInfo
         <cid:0123456789@atlanta.example.com>;
         purpose=EmergencyCallData.DeviceInfo
      Call-Info: <cid:bloorpyhex@atlanta.example.com>;
         purpose=EmergencyCallData.ServiceInfo
      Call-Info: <cid:aaabbb@atlanta.example.com>;
         purpose=EmergencyCallData.ProviderInfo
      Geolocation: <https://ls.example.net:9768/357yc6s64ceyoiuy5ax3o>
      Geolocation-Routing: yes
      Accept: application/sdp, application/pidf+xml,
         application/EmergencyCallData.ProviderInfo+xml
      CSeq: 31862 INVITE
      Contact: <sips:hannes@example.com>
      Content-Type: multipart/mixed; boundary=boundary1
      Content-Length: ...

      --boundary1
      Content-Type: application/sdp

      ...SDP goes here



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      --boundary1
      Content-Type: application/EmergencyCallData.DeviceInfo+xml
      Content-ID: <0123456789@atlanta.example.com>
      Content-Disposition: by-reference;handling=optional

      <?xml version="1.0" encoding="UTF-8"?>
      <dev:EmergencyCallData.DeviceInfo
         xmlns:dev=
         "urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo">
         <dev:DataProviderReference>d4b3072df09876543@[93.184.216.119]
         </dev:DataProviderReference>
         <dev:DeviceClassification>laptop</dev:DeviceClassification>
         <dev:UniqueDeviceID
            TypeOfDeviceID="MAC">00-0d-4b-30-72-df</dev:UniqueDeviceID>
      </dev:EmergencyCallData.DeviceInfo>

      --boundary1
      Content-Type: application/EmergencyCallData.ProviderInfo+xml
      Content-ID: <1234567890@atlanta.example.com>
      Content-Disposition: by-reference;handling=optional

      <?xml version="1.0" encoding="UTF-8"?>
      <pi:EmergencyCallData.ProviderInfo
         xmlns:pi=
         "urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo">
         <pi:DataProviderReference>d4b3072df09876543@[93.184.216.119]
         </pi:DataProviderReference>
         <pi:DataProviderString>Hannes Tschofenig
         </pi:DataProviderString>
         <pi:TypeOfProvider>Client</pi:TypeOfProvider>
         <pi:ContactURI>tel:+1-555-555-0123</pi:ContactURI>
         <pi:Language>en</pi:Language>
         <pi:DataProviderContact
            xmlns="urn:ietf:params:xml:ns:vcard-4.0">
            <vcard>
               <fn><text>Hannes Tschofenig</text></fn>
               <n>
                  <surname>Hannes</surname>
                  <given>Tschofenig</given>
                  <additional/>
                  <prefix/>
                  <suffix>Dipl. Ing.</suffix>
               </n>
               <bday><date>--0203</date></bday>
               <anniversary>
                  <date-time>20090808T1430-0500</date-time>
               </anniversary>
               <gender><sex>M</sex></gender>



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               <lang>
                  <parameters><pref><integer>1</integer></pref>
                  </parameters>
                  <language-tag>de</language-tag>
               </lang>
               <lang>
                  <parameters><pref><integer>2</integer></pref>
                  </parameters>
                  <language-tag>en</language-tag>
               </lang>
               <adr>
                  <parameters>
                     <type><text>work</text></type>
                     <label><text>Hannes Tschofenig
                         Linnoitustie 6
                         Espoo, Finland
                         02600</text></label>
                  </parameters>
                  <pobox/>
                  <ext/>
                  <street>Linnoitustie 6</street>
                  <locality>Espoo</locality>
                  <region>Uusimaa</region>
                  <code>02600</code>
                  <country>Finland</country>
               </adr>
               <adr>
                  <parameters>
                     <type><text>home</text></type>
                     <label><text>Hannes Tschofenig
                         c/o Hotel DuPont
                         42 W 11th St
                         Wilmington, DE 19801
                         USA</text></label>
                  </parameters>
                  <pobox/>
                  <ext/>
                  <street>42 W 11th St</street>
                  <locality>Wilmington</locality>
                  <region>DE</region>
                  <code>19801</code>
                  <country>USA</country>
               </adr>
               <tel>
                  <parameters>
                     <type>
                     <text>work</text>
                     <text>voice</text>



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                     </type>
                  </parameters>
                  <uri>tel:+358 50 4871445</uri>
               </tel>
               <tel>
                  <parameters>
                     <type>
                        <text>home</text>
                        <text>voice</text>
                     </type>
                  </parameters>
                  <uri>tel:+1-555-555-0123</uri>
               </tel>
               <email>
                  <parameters><type><text>work</text></type>
                  </parameters>
                  <text>hannes.tschofenig@nsn.com</text>
               </email>
               <geo>
                  <parameters><type><text>work</text></type>
                  </parameters>
                  <uri>geo:60.210796,24.812924</uri>
               </geo>
               <geo>
                  <parameters><type><text>home</text></type>
                  </parameters>
                  <uri>geo:39.746537,-75.548027</uri>
               </geo>
               <key>
                  <parameters>
                     <type><text>home</text></type>
                  </parameters>
                  <uri>https://www.example.com/key.asc</uri>
               </key>
               <tz><text>Finland/Helsinki</text></tz>
               <url>
                  <parameters><type><text>home</text></type>
                  </parameters>
                  <uri>http://example.com/hannes.tschofenig</uri>
               </url>
            </vcard>
         </pi:DataProviderContact>
      </pi:EmergencyCallData.ProviderInfo>

      --boundary1
      Content-Type: application/EmergencyCallData.ServiceInfo+xml
      Content-ID: <bloorpyhex@atlanta.example.com>
      Content-Disposition: by-reference;handling=optional



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      <?xml version="1.0" encoding="UTF-8"?>
      <svc:EmergencyCallData.ServiceInfo
         xmlns:svc=
            "urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo">
         <svc:DataProviderReference>string0987654321@example.org
         </svc:DataProviderReference>
         <svc:ServiceEnvironment>Residence</svc:ServiceEnvironment>
         <svc:ServiceType>VOIP</svc:ServiceType>
         <svc:ServiceMobility>Unknown</svc:ServiceMobility>
      </svc:EmergencyCallData.ServiceInfo>

      --boundary1
      Content-Type: application/EmergencyCallData.ProviderInfo+xml
      Content-ID: <aaabbb@atlanta.example.com>
      Content-Disposition: by-reference;handling=optional

      <?xml version="1.0" encoding="UTF-8"?>
      <pi:EmergencyCallData.ProviderInfo
         xmlns:pi=
         "urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo">
         <pi:DataProviderReference>string0987654321@example.org
         </pi:DataProviderReference>
         <pi:DataProviderString>Exemplar VoIP Provider
         </pi:DataProviderString>
         <pi:ProviderID>urn:nena:companyid:ID123</pi:ProviderID>
         <pi:ProviderIDSeries>NENA</pi:ProviderIDSeries>
         <pi:TypeOfProvider>Service Provider</pi:TypeOfProvider>
         <pi:ContactURI>sip:voip-provider@example.com</pi:ContactURI>
         <pi:Language>en</pi:Language>
         <pi:DataProviderContact
            xmlns="urn:ietf:params:xml:ns:vcard-4.0">
            <vcard>
               <fn><text>John Doe</text></fn>
               <n>
                  <surname>John</surname>
                  <given>Doe</given>
                  <additional/>
                  <prefix/>
                  <suffix/>
               </n>
               <bday><date>--0203</date></bday>
               <anniversary>
                  <date-time>20090808T1430-0500</date-time>
               </anniversary>
               <gender><sex>M</sex></gender>
               <lang>
                  <parameters><pref><integer>1</integer></pref>
                  </parameters>



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                  <language-tag>en</language-tag>
               </lang>
               <org>
                  <parameters><type><text>work</text></type>
                  </parameters>
                  <text>Exemplar VoIP Provider</text>
               </org>
               <adr>
                  <parameters>
                     <type><text>work</text></type>
                     <label><text>John Doe
                         123 Middle Street
                         The Sticks, IA 50055</text></label>
                  </parameters>
                  <pobox/>
                  <ext/>
                  <street>123 Middle Street</street>
                  <locality>The Sticks</locality>
                  <region>IA</region>
                  <code>50055</code>
                  <country>USA</country>
               </adr>
               <tel>
                  <parameters>
                     <type>
                        <text>work</text>
                        <text>voice</text>
                        <text>main-number</text>
                     </type>
                  </parameters>
                  <uri>sips:john.doe@example.com</uri>
               </tel>
               <email>
                  <parameters><type><text>work</text></type>
                  </parameters>
                  <text>john.doe@example.com</text>
               </email>
               <geo>
                  <parameters><type><text>work</text></type>
                  </parameters>
                  <uri>geo:41.761838,-92.963268</uri>
               </geo>
               <tz><text>America/Chicago</text></tz>
               <url>
                  <parameters><type><text>home</text></type>
                  </parameters>
                  <uri>http://www.example.com/john.doe</uri>
               </url>



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            </vcard>
         </pi:DataProviderContact>
      </pi:EmergencyCallData.ProviderInfo>
      --boundary1--

     Figure 17: VoIP Provider Sending SIP INVITE with Additional Data

   Finally, the PSAP requests location information from the access
   network provider.  The response is shown in Figure 18.  Along with
   the location information, additional data is provided in the
   <provided-by> element of the PIDF-LO.  This request and response is
   step #4.

   <?xml version="1.0" encoding="UTF-8"?>
   <presence xmlns="urn:ietf:params:xml:ns:pidf"
   xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
   xmlns:gbp="urn:ietf:params:xml:ns:pidf:geopriv10:basicPolicy"
   xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model"
   entity="pres:alice@atlanta.example.com">
      <dm:device id="target123-1">
      <gp:geopriv>
      <gp:location-info>
         <civicAddress
            xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr">
            <country>US</country>
            <A1>DE</A1>
            <A3>Wilmington</A3>
            <PRD>W</PRD>
            <RD>11th</RD>
            <STS>Street</STS>
            <HNO>42</HNO>
            <NAM>The Hotel DuPont</NAM>
            <PC>19801</PC>
         </civicAddress>
      </gp:location-info>
      <gp:usage-rules>
         <gbp:retransmission-allowed>true
         </gbp:retransmission-allowed>
         <gbp:retention-expiry>2013-12-10T20:00:00Z
         </gbp:retention-expiry>
      </gp:usage-rules>
      <gp:method>802.11</gp:method>

      <gp:provided-by
         xmlns="urn:ietf:params:xml:ns:EmergencyCallData">






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         <EmergencyCallDataReference
            purpose="EmergencyCallData.ServiceInfo"
            ref="https://example.com/ref2" />

         <EmergencyCallDataValue>
            <EmergencyCallData.ProviderInfo
               xmlns=
               "urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo">
               <DataProviderReference>88QV4FpfZ976T@example.com
               </DataProviderReference>
               <DataProviderString>Diamond State Exemplar
               </DataProviderString>
               <ProviderID>urn:nena:companyid:diamond</ProviderID>
               <ProviderIDSeries>NENA</ProviderIDSeries>
               <TypeOfProvider>Access Network Provider</TypeOfProvider>
               <ContactURI>tel:+1-302-555-0000</ContactURI>
               <Language>en</Language>
            </EmergencyCallData.ProviderInfo>

            <EmergencyCallData.Comment
               xmlns="urn:ietf:params:xml:ns:EmergencyCallData:Comment">
               <DataProviderReference>88QV4FpfZ976T@example.com
               </DataProviderReference>
               <Comment xml:lang="en">This is an example text.</Comment>
            </EmergencyCallData.Comment>

         </EmergencyCallDataValue>
      </gp:provided-by>

      </gp:geopriv>
      <dm:deviceID>mac:00-0d-4b-30-72-df</dm:deviceID>
      <dm:timestamp>2013-07-09T20:57:29Z</dm:timestamp>
      </dm:device>
   </presence>

           Figure 18: Access Network Provider Returning PIDF-LO
                           with Additional Data

8.  XML Schemas

   This section defines the XML schemas of the five data blocks.
   Additionally, the provided-by schema is specified.









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8.1.  EmergencyCallData.ProviderInfo XML Schema

   <?xml version="1.0"?>
   <xs:schema
      targetNamespace=
           "urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo"
      xmlns:xs="http://www.w3.org/2001/XMLSchema"
      xmlns:pi="urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo"
      xmlns:xml="http://www.w3.org/XML/1998/namespace"
      xmlns:xc="urn:ietf:params:xml:ns:vcard-4.0"
      elementFormDefault="qualified"
      attributeFormDefault="unqualified">

      <xs:import namespace="http://www.w3.org/XML/1998/namespace"
           schemaLocation="http://www.w3.org/2009/01/xml.xsd"/>

       <xs:import namespace="urn:ietf:params:xml:ns:vcard-4.0"
           schemaLocation="vcard.xsd"/>

       <xs:element
           name="EmergencyCallData.ProviderInfo"
           type="pi:ProviderInfoType"/>

       <xs:simpleType name="SubcontractorPriorityType">
          <xs:restriction base="xs:string">
               <xs:enumeration value="sub"/>
               <xs:enumeration value="main"/>
          </xs:restriction>
       </xs:simpleType>

       <xs:complexType name="ProviderInfoType">
               <xs:sequence>
                   <xs:element name="DataProviderReference"
                       type="xs:token" minOccurs="1" maxOccurs="1"/>

                   <xs:element name="DataProviderString"
                       type="xs:string" minOccurs="1" maxOccurs="1"/>

                   <xs:element name="ProviderID"
                       type="xs:string" minOccurs="0" maxOccurs="1"/>

                   <xs:element name="ProviderIDSeries"
                       type="xs:string" minOccurs="0" maxOccurs="1"/>

                   <xs:element name="TypeOfProvider"
                       type="xs:token" minOccurs="1" maxOccurs="1"/>





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                   <xs:element name="ContactURI" type="xs:anyURI"
                       minOccurs="1" maxOccurs="1"/>

   <xs:element name="Language" minOccurs="1" maxOccurs="unbounded">
       <xs:simpleType>
         <xs:restriction base="xs:string">
           <xs:pattern
   value="([a-z]{2,3}((-[a-z]{3}){0,3})?|[a-z]{4,8})
   (-[a-z]{4})?(-([a-z]{2}|\d{3}))?(-([0-9a-z]{5,8}|
   \d[0-9a-z]{3}))*(-[0-9a-wyz](-[0-9a-z]{2,8})+)*
   (-x(-[0-9a-z]{1,8})+)?|x(-[0-9a-z]{1,8})+|[a-z]{1,3}
   (-[0-9a-z]{2,8}){1,2}"/>
         </xs:restriction>
       </xs:simpleType>
     </xs:element>

                   <xs:element name="DataProviderContact"
                       minOccurs="0" maxOccurs="1">
                     <xs:complexType>
                        <xs:sequence>
                          <xs:element minOccurs="0"
                              maxOccurs="unbounded" ref="xc:vcard"/>
                        </xs:sequence>
                     </xs:complexType>
                   </xs:element>

                   <xs:element name="SubcontractorPrincipal"
                       type="xs:string" minOccurs="0" maxOccurs="1"/>

                   <xs:element name="SubcontractorPriority"
                       type="pi:SubcontractorPriorityType"
                       minOccurs="0" maxOccurs="1"/>

                   <xs:any namespace="##other" processContents="lax"
                       minOccurs="0" maxOccurs="unbounded"/>
               </xs:sequence>
           </xs:complexType>

   </xs:schema>

           Figure 19: EmergencyCallData.ProviderInfo XML Schema










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8.2.  EmergencyCallData.ServiceInfo XML Schema

   <?xml version="1.0"?>
   <xs:schema
        targetNamespace=
            "urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo"
        xmlns:xs="http://www.w3.org/2001/XMLSchema"
        xmlns:svc="urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo"
        xmlns:xml="http://www.w3.org/XML/1998/namespace"
        elementFormDefault="qualified"
        attributeFormDefault="unqualified">

        <xs:import namespace="http://www.w3.org/XML/1998/namespace"
                   schemaLocation="http://www.w3.org/2001/xml.xsd"/>

       <xs:element name="EmergencyCallData.ServiceInfo"
           type="svc:ServiceInfoType"/>

       <xs:complexType name="ServiceInfoType">
               <xs:sequence>
                  <xs:element name="DataProviderReference"
                      type="xs:token" minOccurs="1" maxOccurs="1"/>

                   <xs:element name="ServiceEnvironment"
                     type="xs:string" minOccurs="0" maxOccurs="1"/>

                   <xs:element name="ServiceType"
                     type="xs:string" minOccurs="1"
                     maxOccurs="unbounded"/>

                   <xs:element name="ServiceMobility"
                     type="xs:string" minOccurs="1" maxOccurs="1"/>

                   <xs:any namespace="##other" processContents="lax"
                      minOccurs="0" maxOccurs="unbounded"/>
               </xs:sequence>
       </xs:complexType>

   </xs:schema>

            Figure 20: EmergencyCallData.ServiceInfo XML Schema










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8.3.  EmergencyCallData.DeviceInfo XML Schema

   <?xml version="1.0"?>
   <xs:schema
        targetNamespace=
           "urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo"
        xmlns:xs="http://www.w3.org/2001/XMLSchema"
        xmlns:dev="urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo"
        xmlns:xml="http://www.w3.org/XML/1998/namespace"
        elementFormDefault="qualified"
        attributeFormDefault="unqualified">

        <xs:import namespace="http://www.w3.org/XML/1998/namespace"
                   schemaLocation="http://www.w3.org/2001/xml.xsd"/>

       <xs:element name="EmergencyCallData.DeviceInfo"
           type="dev:DeviceInfoType"/>

       <xs:complexType name="DeviceInfoType">
               <xs:sequence>
                  <xs:element name="DataProviderReference"
                       type="xs:token" minOccurs="1" maxOccurs="1"/>

                   <xs:element name="DeviceClassification"
                       type="xs:string" minOccurs="0" maxOccurs="1"/>

                   <xs:element name="DeviceMfgr"
                       type="xs:string" minOccurs="0" maxOccurs="1"/>

                   <xs:element name="DeviceModelNr"
                       type="xs:string" minOccurs="0" maxOccurs="1"/>

                   <xs:element name="UniqueDeviceID" minOccurs="0"
                               maxOccurs="unbounded">
                     <xs:complexType>
                       <xs:simpleContent>
                         <xs:extension base="xs:string">
                           <xs:attribute name="TypeOfDeviceID"
                                         type="xs:string"
                                         use="required"/>
                         </xs:extension>
                       </xs:simpleContent>
                     </xs:complexType>
                   </xs:element>

                   <xs:element name="DeviceSpecificData"
                       type="xs:anyURI" minOccurs="0" maxOccurs="1"/>




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                   <xs:element name="DeviceSpecificType"
                       type="xs:string" minOccurs="0" maxOccurs="1"/>

                   <xs:any namespace="##other" processContents="lax"
                       minOccurs="0" maxOccurs="unbounded"/>
               </xs:sequence>
           </xs:complexType>

   </xs:schema>

            Figure 21: EmergencyCallData.DeviceInfo XML Schema








































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8.4.  EmergencyCallData.SubscriberInfo XML Schema

   <?xml version="1.0"?>
       <xs:schema
           targetNamespace=
               "urn:ietf:params:xml:ns:EmergencyCallData:SubscriberInfo"
       xmlns:xs="http://www.w3.org/2001/XMLSchema"
       xmlns:sub=
           "urn:ietf:params:xml:ns:EmergencyCallData:SubscriberInfo"
       xmlns:xc="urn:ietf:params:xml:ns:vcard-4.0"
       xmlns:xml="http://www.w3.org/XML/1998/namespace"
       elementFormDefault="qualified"
       attributeFormDefault="unqualified">

       <xs:import namespace="http://www.w3.org/XML/1998/namespace"
           schemaLocation="http://www.w3.org/2001/xml.xsd"/>

       <xs:import namespace="urn:ietf:params:xml:ns:vcard-4.0"
             schemaLocation="vcard.xsd"/>

       <xs:element name="EmergencyCallData.SubscriberInfo"
           type="sub:SubscriberInfoType"/>

       <xs:complexType name="SubscriberInfoType">
           <xs:sequence>
               <xs:element name="DataProviderReference" type="xs:token"
                  minOccurs="1" maxOccurs="1"/>
               <xs:element name="SubscriberData">
                   <xs:complexType>
                       <xs:sequence>
                           <xs:element ref="xc:vcard"
                           maxOccurs="unbounded"/>
                       </xs:sequence>
                   </xs:complexType>
               </xs:element>

               <xs:any namespace="##other" processContents="lax"
                 minOccurs="0" maxOccurs="unbounded"/>

           </xs:sequence>
           <xs:attribute name="privacyRequested"
              type="xs:boolean" use="required"/>

       </xs:complexType>
   </xs:schema>

          Figure 22: EmergencyCallData.SubscriberInfo XML Schema




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8.5.  EmergencyCallData.Comment XML Schema

   <?xml version="1.0"?>
   <xs:schema
        targetNamespace=
           "urn:ietf:params:xml:ns:EmergencyCallData:Comment"
        xmlns:xs="http://www.w3.org/2001/XMLSchema"
        xmlns:com="urn:ietf:params:xml:ns:EmergencyCallData:Comment"
        xmlns:xml="http://www.w3.org/XML/1998/namespace"
        elementFormDefault="qualified"
        attributeFormDefault="unqualified">

        <xs:import namespace="http://www.w3.org/XML/1998/namespace"
                   schemaLocation="http://www.w3.org/2001/xml.xsd"/>

       <xs:element name="EmergencyCallData.Comment"
           type="com:CommentType"/>

       <xs:complexType name="CommentType">
               <xs:sequence>
                   <xs:element name="DataProviderReference"
                     type="xs:token" minOccurs="1" maxOccurs="1"/>

                   <xs:element name="Comment"
                       type="com:CommentSubType" minOccurs="0"
                       maxOccurs="unbounded"/>

                   <xs:any namespace="##other" processContents="lax"
                       minOccurs="0" maxOccurs="unbounded"/>
              </xs:sequence>
           </xs:complexType>

       <xs:complexType name="CommentSubType">
        <xs:simpleContent>
         <xs:extension base="xs:string">
          <xs:attribute ref="xml:lang"/>
         </xs:extension>
        </xs:simpleContent>
       </xs:complexType>

   </xs:schema>

              Figure 23: EmergencyCallData.Comment XML Schema








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8.6.  provided-by XML Schema

   This section defines the provided-by schema.

<?xml version="1.0"?>
<xs:schema
    targetNamespace="urn:ietf:params:xml:ns:EmergencyCallData"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:ad="urn:ietf:params:xml:ns:EmergencyCallData"
    xmlns:xml="http://www.w3.org/XML/1998/namespace"
    xmlns:pi="urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo"
    xmlns:svc="urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo"
    xmlns:dev="urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo"
    xmlns:sub="urn:ietf:params:xml:ns:EmergencyCallData:SubscriberInfo"
    xmlns:com="urn:ietf:params:xml:ns:EmergencyCallData:Comment"
    elementFormDefault="qualified"
    attributeFormDefault="unqualified">

    <xs:import
     namespace="urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo"
     schemaLocation="ProviderInfo.xsd"/>
    <xs:import
     namespace="urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo"
     schemaLocation="ServiceInfo.xsd"/>
    <xs:import
     namespace="urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo"
     schemaLocation="DeviceInfo.xsd"/>
    <xs:import
     namespace="urn:ietf:params:xml:ns:EmergencyCallData:SubscriberInfo"
     schemaLocation="SubscriberInfo.xsd"/>
    <xs:import
     namespace="urn:ietf:params:xml:ns:EmergencyCallData:Comment"
     schemaLocation="Comment.xsd"/>
    <xs:element name="EmergencyCallDataReference" type="ad:ByRefType"/>
    <xs:element name="EmergencyCallDataValue"
    type="ad:EmergencyCallDataValueType"/>
    <!-- Additional Data By Reference -->
    <xs:complexType name="ByRefType">
        <xs:sequence>
            <xs:any namespace="##other" processContents="lax"
            minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
        <xs:attribute name="purpose" type="xs:token" use="required"/>
        <xs:attribute name="ref" type="xs:anyURI" use="required"/>
    </xs:complexType>
    <!-- Additional Data By Value -->
    <xs:complexType name="EmergencyCallDataValueType">
      <xs:sequence>



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        <xs:element ref="pi:EmergencyCallData.ProviderInfo"
                minOccurs="0" maxOccurs="unbounded"/>
        <xs:element ref="svc:EmergencyCallData.ServiceInfo"
                minOccurs="0" maxOccurs="unbounded"/>
        <xs:element ref="dev:EmergencyCallData.DeviceInfo"
                minOccurs="0" maxOccurs="unbounded"/>
        <xs:element ref="sub:EmergencyCallData.SubscriberInfo"
                minOccurs="0" maxOccurs="unbounded"/>
        <xs:element ref="com:EmergencyCallData.Comment"
                minOccurs="0" maxOccurs="unbounded"/>
        <xs:any namespace="##other" processContents="lax"
         minOccurs="0" maxOccurs="unbounded"/>
      </xs:sequence>
    </xs:complexType>
</xs:schema>

                     Figure 24: provided-by XML Schema

9.  Security Considerations

   The data structures described in this document contain information
   usually considered private.  When information is provided by value,
   entities that are a party to the SIP signaling (such as proxy servers
   and back-to-back user agents) will have access to it and need to
   protect it against inappropriate disclosure.  An entity that is able
   to eavesdrop on the SIP signaling will also have access.  Some
   Internet access types (such as in-the-clear Wi-Fi) are more
   vulnerable than others (such as 3G or 4G cellular data traffic) to
   eavesdropping.  Mechanisms that protect against eavesdropping (such
   as TLS version 1.2 or later) SHOULD be preferentially used whenever
   feasible.  (This requirement is not a "MUST" because there is an
   existing deployed base of clear-text SIP, and also because, as an
   emergency call, it is more important for the call to go through than
   for it to be protected; for example, the call MUST proceed even if
   the TLS negotiation or certificate verification fails for whatever
   reason.)  When information is provided by reference, TLS mutual
   authentication is REQUIRED.  That is, HTTPS is REQUIRED for
   dereferencing, the requester MUST use a client certificate to
   authenticate the HTTP request, and the provider of the information is
   REQUIRED to validate the credentials provided by the requester.
   While the creation of a public key infrastructure (PKI) that has
   global scope might be difficult, the alternatives to creating devices
   and services that can provide critical information securely are more
   daunting.  The provider of the information MAY enforce any policy it
   wishes to use, but PSAPs and responder agencies are strongly advised
   to deploy a PKI so that providers of additional data can check the
   certificate of the client (the requester) and decide the appropriate
   policy to enforce based on that certificate.



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   TLS MUST be version 1.2 or later.  It is RECOMMENDED to use only
   cipher suites that offer Perfect Forward Secrecy (PFS) and avoid
   Cipher Block Chaining (CBC) and to follow the recommendations in BCP
   195 [RFC7525].

   Ideally, the PSAP and emergency responders will be given credentials
   signed by an authority trusted by the data provider.  In most
   circumstances, nationally recognized credentials are sufficient; the
   emergency services community within a country can arrange a PKI, data
   providers can be provisioned with the root Certification Authority
   (CA) public key for the country.  Some nations are developing a PKI
   for this and related purposes.  Since calls could be made from
   devices where the device and/or the service provider(s) is not local
   to the emergency services authorities, globally recognized
   credentials are useful.  This might be accomplished by extending the
   notion of the "forest guide" described in [RFC5582] to allow the
   forest guide to provide the credential of the PKI root for areas for
   which it has coverage information, but standards for such a mechanism
   are not yet available.  In its absence, the data provider needs to
   obtain by out-of-band means the root CA credentials for any areas to
   which it is willing to provide additional data.  With the credential
   of the root CA for a national emergency services PKI, the data
   provider server can validate the credentials of an entity requesting
   additional data by reference.

   The data provider also needs a credential that can be verified by the
   emergency services to know that it is receiving data from an
   authorized server.  The emergency services authorities could provide
   credentials, distinguishable from credentials provided to emergency
   responders and PSAPs, which could be used to validate data providers.
   Such credentials would have to be acceptable to any PSAP or responder
   that could receive a call with additional data supplied by that
   provider.  This would be extensible to global credential validation
   using the forest guide as mentioned above.  In the absence of such
   credentials, the emergency services authorities could maintain a list
   of local data providers' credentials as provided to them out of band.
   At a minimum, the emergency services authorities could obtain a
   credential from the DNS entry of the domain in the additional data
   URI (e.g., using DNS-Based Authentication of Named Entities (DANE)
   [RFC6698]) to at least validate that the server is known to the
   domain providing the URI.

   When devices provide data by reference, the credential validation
   issues are similar to when service providers do so, and while the
   solutions are the same, the challenges of doing so for every device
   are obviously more difficult, especially when considering root
   certificate updates, revocation lists, etc.  However, in general,
   devices are not expected to provide data directly by reference, but



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   rather to either provide data by value or upload the data to a server
   that can more reliably make it available and more easily enforce
   security policy.  Devices that do provide data directly by reference,
   which might include fixed-location sensors, will need to be capable
   of handling this.

   Neither service providers nor devices will supply private information
   unless the call is recognized as an emergency call.  In cellular
   telephony systems (such as those using 3GPP IMS), there are different
   procedures for an originating device to place an emergency call
   versus a normal call.  If a call that is really an emergency call is
   initiated as a normal call and the cellular service provider
   recognizes this, 3GPP IMS permits the service provider to either
   accept the call anyway or reject it with a specific code that
   instructs the device to retry the call as an emergency call.  Service
   providers ought to choose the latter, otherwise the device will not
   include the information specified in this document (since the device
   didn't recognize the call as being an emergency call).

10.  Privacy Considerations

   This document enables functionality for conveying additional
   information about the caller and the caller's device and service to
   the callee.  Some of this information is personal data and therefore
   privacy concerns arise.  An explicit privacy indicator for
   information directly relating to the caller's identity is defined and
   use is mandatory.  However, observance of this request for privacy
   and which information it relates to is determined by the destination
   jurisdiction (which replicates functionality provided in some legacy
   emergency services systems).

   There are a number of privacy concerns with non-emergency real-time
   communication services that are also applicable to emergency calling.
   Data protection regulation worldwide has, however, decided to create
   exceptions for emergency services since the drawbacks of disclosing
   personal data are outweighed by the benefit for the emergency caller.
   Hence, the data protection rights of individuals are commonly waived
   for emergency situations.  There are, however, still various
   countries that offer some degree of anonymity for the caller towards
   PSAP call takers.

   The functionality defined in this document far exceeds the amount of
   information sharing available in the legacy POTS system.  For this
   reason, there are additional privacy threats to consider, which are
   described in more detail in [RFC6973].






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   Stored Data Compromise:  There is an increased risk of stored data
      compromise since additional data is collected and stored in
      databases.  Without adequate measures to secure stored data from
      unauthorized or inappropriate access at access network providers,
      service providers, end devices, as well as PSAPs, individuals are
      exposed to potential financial, reputational, or physical harm.

   Misattribution:  If the personal data collected and conveyed is
      incorrect or inaccurate, then this can lead to misattribution.
      Misattribution occurs when data or communications related to one
      individual are attributed to another.

   Identification:  By the nature of the additional data and its
      capability to provide much richer information about the caller,
      the call, and the location, the calling party is identified in a
      much better way.  Some users could feel uncomfortable with this
      degree of information sharing even in emergency services
      situations.

   Secondary Use:  There is a risk of secondary use, which is the use of
      collected information about an individual without the individual's
      consent for a purpose different from that for which the
      information was collected.  The stated purpose of the additional
      data is for emergency services purposes, but theoretically the
      same information could be used for any other call as well.
      Additionally, parties involved in the emergency call could retain
      the obtained information and reuse it for other, non-emergency
      services purposes.  While technical measures are not in place to
      prevent such secondary reuse, policy, legal, regulatory, and other
      non-technical approaches can be effective.

   Disclosure:  When the data defined in this document is not properly
      protected (while in transit with traditional communication
      security techniques and while stored using access control
      mechanisms), there is the risk of disclosure, which is the
      revelation of private information about an individual.

   To mitigate these privacy risks, the following countermeasures can be
   taken:

   In regions where callers can elect to suppress certain personally
   identifying information, network or PSAP functionality can inspect
   privacy flags within the SIP headers to determine what information
   can be passed, stored, or displayed to comply with local policy or
   law.  RFC 3325 [RFC3325] defines the 'id' priv-value token.  The
   presence of this privacy type in a Privacy header field indicates





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   that the user would like the network asserted identity to be kept
   private with respect to SIP entities outside the trust domain with
   which the user authenticated, including the PSAP.

   This document defines various data structures that contain privacy-
   sensitive data such as, for example, identifiers for the device
   (e.g., serial number and MAC address) or account/SIM (e.g., IMSI),
   contact information for the user, and location of the caller.  Local
   regulations may govern which data is provided in emergency calls, but
   in general, the emergency call system is aided by the information
   described in this document.  There is a trade-off between the privacy
   considerations and the utility of the data.  For protection, this
   specification requires all retrieval of data passed by reference to
   be protected against eavesdropping and alteration via communication
   security techniques (namely TLS).  Furthermore, security safeguards
   are required to prevent unauthorized access to stored data.  Various
   security incidents over at least the past few decades have shown that
   data breaches are not uncommon and are often caused by lack of proper
   access control frameworks, software bugs (such as buffer overflows),
   or missing input parsing (such as SQL injection attacks).  The risks
   of data breaches have increased with the obligation for emergency
   services to retain emergency-call-related data for extended periods
   (e.g., several years are the norm).

   Finally, it is also worth highlighting the nature of the SIP
   communication architecture, which introduces additional complications
   for privacy.  Some forms of data can be sent by value in the SIP
   signaling or by reference (a URL in the SIP signaling).  When data is
   sent by value, all intermediaries have access to the data.  As such,
   these intermediaries could also introduce additional privacy risk.
   Therefore, in situations where the conveyed information is privacy
   sensitive and intermediaries are involved, transmitting by reference
   might be appropriate, assuming the source of the data can operate a
   sufficient dereferencing infrastructure and that proper access
   control policies are available for distinguishing the different
   entities dereferencing the reference.  Without access control
   policies, any party in possession of the reference is able to resolve
   the reference and to obtain the data, including intermediaries.













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11.  IANA Considerations

11.1.  Emergency Call Additional Data Registry

   This document creates a new registry called 'Emergency Call
   Additional Data' with a number of sub-registries.

   For several of the sub-registries, "Expert Review" is the criteria
   for adding new entries.  As discussed in Section 5, it can be
   counterproductive to register new types of data, and as discussed in
   Section 10, data sent as part of an emergency call can be very
   privacy sensitive.  In some cases, it is anticipated that various
   standards bodies dealing with emergency services might need to
   register new values, and in those cases, text below advises the
   designed expert to verify that the entity requesting the registration
   is relevant (e.g., a recognized emergency-services-related Standards
   Development Organization (SDO)).  In other cases, especially those
   where the trade-off between the potential benefit versus danger of
   new registrations is more conservative (such as Section 11.1.9),
   "Specification Required" is the criteria, which is a higher hurdle
   and also implicitly includes an "Expert Review".

   The following sub-registries are created for this registry.

11.1.1.  Provider ID Series Registry

   This document creates a new sub-registry called "Provider ID Series".
   As defined in [RFC5226], this registry operates under "Expert Review"
   rules.  The expert should determine that the entity requesting a new
   value is a legitimate issuer of service provider IDs suitable for use
   in Additional Call Data.

   Private entities issuing or using internally generated IDs are
   encouraged to register here and to ensure that all IDs they issue or
   use are unique.  This guarantees that IDs issued or used by the
   entity are globally unique and distinguishable from other IDs issued
   or used by the same or a different entity.  (Some organizations, such
   as NENA, issue IDs that are unique among all IDs they issue, so an
   entity using a combination of its NENA ID and the fact that it is
   from NENA is globally unique.  Other entities might not have an ID
   issued by an organization such as NENA, so they are permitted to use
   their domain name, but if so, it needs to be unique.)

   The content of this registry includes:

   Name:  An identifier to be used in the 'ProviderIDSeries' element.

   Source:  The full name of the organization issuing the identifiers.



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   URL:  A URL to the organization for further information.

   The initial set of values is listed in Figure 1.

11.1.2.  Service Environment Registry

   This document creates a new sub-registry called "Service
   Environment".  As defined in [RFC5226], this registry operates under
   "Expert Review" rules.  The expert should determine that the entity
   requesting a new value is relevant for this service element (e.g., a
   recognized emergency-services-related SDO) and that the new value is
   distinct from existing values, and its use is unambiguous.

   The content of this registry includes:

   Token:  The value to be used in the <ServiceEnvironment> element.

   Description:  A short description of the value.

   The initial set of values is listed in Figure 4.

11.1.3.  Service Type Registry

   This document creates a new sub-registry called "Service Type".  As
   defined in [RFC5226], this registry operates under "Expert Review"
   rules.  The expert should determine that the entity requesting a new
   value is relevant for this service element (e.g., a recognized
   emergency-services-related SDO) and that the requested value is
   clearly distinct from other values so that there is no ambiguity as
   to when the value is to be used or which value is to be used.

   The content of this registry includes:

   Name:  The value to be used in the <ServiceType> element.

   Description:  A short description of the value.

   The initial set of values is listed in Figure 5.

11.1.4.  Service Mobility Registry

   This document creates a new sub-registry called "Service Mobility".
   As defined in [RFC5226], this registry operates under "Expert Review"
   rules.  The expert should determine that the entity requesting a new
   value is relevant for this service element (e.g., a recognized
   emergency-services-related SDO) and that the requested value is
   clearly distinct from other values so that there is no ambiguity as
   to when the value is to be used or which value is to be used.



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   The content of this registry includes:

   Token:  The value used in the <ServiceMobility> element.

   Description:  A short description of the value.

   The initial set of values is listed in Figure 6.

11.1.5.  Type of Provider Registry

   This document creates a new sub-registry called "Type of Provider".
   As defined in [RFC5226], this registry operates under "Expert Review"
   rules.  The expert should determine that the proposed new value is
   distinct from existing values and appropriate for use in the
   <TypeOfServicerProvider> element

   The content of this registry includes:

   Token:  The value used in the <TypeOfProvider> element.

   Description:  A short description of the type of service provider.

   The initial set of values is defined in Figure 2.

11.1.6.  Device Classification Registry

   This document creates a new sub-registry called "Device
   Classification".  As defined in [RFC5226], this registry operates
   under "Expert Review" rules.  The expert should consider whether the
   proposed class is unique from existing classes, and the definition of
   the class will be clear to implementors and PSAPs/responders.

   The content of this registry includes:

   Token:  Value used in the <DeviceClassification> element.

   Description:  Short description identifying the device type.

   The initial set of values is defined in Figure 8.

11.1.7.  Device ID Type Registry

   This document creates a new sub-registry called "Device ID Type".  As
   defined in [RFC5226], this registry operates under "Expert Review"
   rules.  The expert should ascertain that the proposed type is well
   understood and provides information that PSAPs and responders are
   able to use to uniquely identify a device.  (For example, a biometric




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   fingerprint used to authenticate a device would not normally be used
   by a PSAP or responder to identify a device.)

   The content of this registry includes:

   Token:  The value to be placed in the <TypeOfDeviceID> element.

   Description:  Short description identifying the type of the device
      ID.

   The initial set of values is defined in Figure 9.

11.1.8.  Device/Service Data Type Registry

   This document creates a new sub-registry called "Device/Service Data
   Type".  As defined in [RFC5226], this registry operates under
   "Specification Required" rules, which include an explicit "Expert
   Review".  The designated expert should ascertain that the proposed
   type is well understood and provides information useful to PSAPs and
   responders.  The specification must contain a complete description of
   the data and a precise format specification suitable to allow
   interoperable implementations.

   The content of this registry includes:

   Token:  The value to be placed in the <DeviceSpecificType> element.

   Description:  Short description identifying the data.

   Specification:  Citation for the specification of the data.

   The initial set of values is listed in Figure 10.

11.1.9.  Emergency Call Data Types Registry

   This document creates a new sub-registry called "Emergency Call Data
   Types".  As defined in [RFC5226], this registry operates under
   "Specification Required" rules, which include an explicit "Expert
   Review".  The expert is responsible for verifying that the document
   contains a complete and clear specification, and the proposed
   functionality does not obviously duplicate existing functionality.
   The expert is also responsible for verifying that the block is
   correctly categorized per the description of the categories in
   Section 1.

   The registry contains an entry for every data block that can be sent
   with an emergency call using the mechanisms as specified in this
   document.  Each data block is identified by the 'root' of its MIME



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   media subtype (which is the part after 'EmergencyCallData.').  If the
   MIME media subtype does not start with 'EmergencyCallData.', then it
   cannot be registered here nor used in a Call-Info header field as
   specified in this document.  The subtype MAY exist under any MIME
   media type (although most commonly under 'application/', this is NOT
   REQUIRED); however, to be added to the registry, the 'root' needs to
   be unique regardless of the MIME media type.

   The content of this registry includes:

   Token:  The root of the data's MIME media subtype (not including the
      'EmergencyCallData' prefix and any suffix such as '+xml').

   Data About:  A hint as to if the block is considered descriptive of
      the call, the caller, or the location (or is applicable to more
      than one), which can help PSAPs and other entities determine if
      they wish to process the block.  Note that this is only a hint;
      entities need to consider the block's contents, not just this
      field, when determining if they wish to process the block (which
      is why the field only exists in the registry and is not contained
      within the block).  The value MUST be either 'The Call', 'The
      Caller', 'The Location', or 'Multiple'.  New values are created by
      extending this registry in a subsequent RFC.

   Reference:  The document that describes the data object.

   Note that the tokens in this registry are part of the
   'EmergencyCallData' compound value; when used as a value of the
   'purpose' parameter of a Call-Info header field, the values listed in
   this registry are prefixed by 'EmergencyCallData.' per the
   'EmergencyCallData' registration; see Section 11.2.

   The initial set of values is listed in Figure 25.

      +----------------+--------------+------------+
      | Token          |  Data About  | Reference  |
      +----------------+--------------+------------+
      | ProviderInfo   |   The Call   |  RFC 7852  |
      | ServiceInfo    |   The Call   |  RFC 7852  |
      | DeviceInfo     |   The Call   |  RFC 7852  |
      | SubscriberInfo |   The Call   |  RFC 7852  |
      | Comment        |   The Call   |  RFC 7852  |
      +----------------+--------------+------------+

                Figure 25: Additional Data Blocks Registry






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11.2.  'EmergencyCallData' Purpose Parameter Value

   This document defines the 'EmergencyCallData' value for the 'purpose'
   parameter of the Call-Info header field [RFC3261].  IANA has added
   this document to the list of references for the 'purpose' value of
   Call-Info in the "Header Field Parameters and Parameter Values" sub-
   registry of the "Session Initiation Protocol (SIP) Parameters"
   registry.  Note that 'EmergencyCallData' is a compound value; when
   used as a value of the 'purpose' parameter of a Call-Info header
   field, 'EmergencyCallData' is immediately followed by a dot ('.') and
   a value from the "Emergency Call Data Types" registry; see
   Section 11.1.9.

11.3.  URN Sub-Namespace Registration for <provided-by> Registry Entry

   This section registers the namespace specified in Section 11.5.1 in
   the provided-by registry established by RFC 4119, for usage within
   the <provided-by> element of a PIDF-LO.

   The schema for the <provided-by> element used by this document is
   specified in Section 8.6.

11.4.  MIME Registrations

11.4.1.  MIME Content-Type Registration for 'application/
         EmergencyCallData.ProviderInfo+xml'

   This specification requests the registration of a new MIME media type
   according to the procedures of RFC 6838 [RFC6838] and guidelines in
   RFC 7303 [RFC7303].

      Type name: application

      Subtype name: EmergencyCallData.ProviderInfo+xml

      Mandatory parameters: N/A

      Optional parameters: charset (indicates the character encoding of
      the contents)

      Encoding considerations: Uses XML, which can contain 8-bit
      characters, depending on the character encoding.  See Section 3.2
      of RFC 7303 [RFC7303].

      Security considerations: This content type is designed to carry
      the data provider information, which is a sub-category of
      additional data about an emergency call.  Since this data can
      contain personal information, appropriate precautions are needed



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      to limit unauthorized access, inappropriate disclosure, and
      eavesdropping of personal information.  Please refer to Sections 9
      and 10 for more information.

      Interoperability considerations: N/A

      Published specification: RFC 7852

      Applications that use this media type: Emergency Services

      Additional information:

         Magic Number: N/A

         File Extension: .xml

         Macintosh file type code: 'TEXT'

      Person and email address for further information:
      Hannes Tschofenig, Hannes.Tschofenig@gmx.net

      Intended usage: LIMITED USE

      Author: This specification is a work item of the IETF ECRIT
      working group, with mailing list address <ecrit@ietf.org>.

      Change controller: The IESG <iesg@ietf.org>

11.4.2.  MIME Content-Type Registration for 'application/
         EmergencyCallData.ServiceInfo+xml'

   This specification requests the registration of a new MIME media type
   according to the procedures of RFC 6838 [RFC6838] and guidelines in
   RFC 7303 [RFC7303].

      Type name: application

      Subtype name: EmergencyCallData.ServiceInfo+xml

      Mandatory parameters: N/A

      Optional parameters: charset (indicates the character encoding of
      the contents)

      Encoding considerations: Uses XML, which can contain 8-bit
      characters, depending on the character encoding.  See Section 3.2
      of RFC 7303 [RFC7303].




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      Security considerations: This content type is designed to carry
      the service information, which is a sub-category of additional
      data about an emergency call.  Since this data can contain
      personal information, appropriate precautions are needed to limit
      unauthorized access, inappropriate disclosure, and eavesdropping
      of personal information.  Please refer to Sections 9 and 10 for
      more information.

      Interoperability considerations: N/A

      Published specification: RFC 7852

      Applications that use this media type: Emergency Services

      Additional information:

         Magic Number: N/A

         File Extension: .xml

         Macintosh file type code: 'TEXT'

      Person and email address for further information:
      Hannes Tschofenig, Hannes.Tschofenig@gmx.net

      Intended usage: LIMITED USE

      Author: This specification is a work item of the IETF ECRIT
      working group, with mailing list address <ecrit@ietf.org>.

      Change controller: The IESG <iesg@ietf.org>

11.4.3.  MIME Content-Type Registration for 'application/
         EmergencyCallData.DeviceInfo+xml'

   This specification requests the registration of a new MIME media type
   according to the procedures of RFC 6838 [RFC6838] and guidelines in
   RFC 7303 [RFC7303].

      Type name: application

      Subtype name: EmergencyCallData.DeviceInfo+xml

      Mandatory parameters: N/A

      Optional parameters: charset (indicates the character encoding of
      the contents)




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      Encoding considerations: Uses XML, which can contain 8-bit
      characters, depending on the character encoding.  See Section 3.2
      of RFC 7303 [RFC7303].

      Security considerations: This content type is designed to carry
      device information, which is a sub-category of additional data
      about an emergency call.  Since this data contains personal
      information, appropriate precautions need to be taken to limit
      unauthorized access, inappropriate disclosure to third parties,
      and eavesdropping of this information.  Please refer to Sections 9
      and 10 for more information.

      Interoperability considerations: N/A

      Published specification: RFC 7852

      Applications that use this media type: Emergency Services

      Additional information:

         Magic Number: N/A

         File Extension: .xml

         Macintosh file type code: 'TEXT'

      Person and email address for further information:
      Hannes Tschofenig, Hannes.Tschofenig@gmx.net

      Intended usage: LIMITED USE

      Author: This specification is a work item of the IETF ECRIT
      working group, with mailing list address <ecrit@ietf.org>.

      Change controller: The IESG <iesg@ietf.org>

11.4.4.  MIME Content-Type Registration for 'application/
         EmergencyCallData.SubscriberInfo+xml'

   This specification requests the registration of a new MIME media type
   according to the procedures of RFC 6838 [RFC6838] and guidelines in
   RFC 7303 [RFC7303].

      Type name: application

      Subtype name: EmergencyCallData.SubscriberInfo+xml

      Mandatory parameters: N/A



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      Optional parameters: charset (indicates the character encoding of
      the contents)

      Encoding considerations: Uses XML, which can contain 8-bit
      characters, depending on the character encoding.  See Section 3.2
      of RFC 7303 [RFC7303].

      Security considerations: This content type is designed to carry
      owner/subscriber information, which is a sub-category of
      additional data about an emergency call.  Since this data contains
      personal information, appropriate precautions need to be taken to
      limit unauthorized access, inappropriate disclosure to third
      parties, and eavesdropping of this information.  Please refer to
      Sections 9 and 10 for more information.

      Interoperability considerations: N/A

      Published specification: RFC 7852

      Applications that use this media type: Emergency Services

      Additional information:

         Magic Number: N/A

         File Extension: .xml

         Macintosh file type code: 'TEXT'

      Person and email address for further information:
      Hannes Tschofenig, Hannes.Tschofenig@gmx.net

      Intended usage: LIMITED USE

      Author: This specification is a work item of the IETF ECRIT
      working group, with mailing list address <ecrit@ietf.org>.

      Change controller: The IESG <iesg@ietf.org>

11.4.5.  MIME Content-Type Registration for 'application/
         EmergencyCallData.Comment+xml'

   This specification requests the registration of a new MIME media type
   according to the procedures of RFC 6838 [RFC6838] and guidelines in
   RFC 7303 [RFC7303].

      Type name: application




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      Subtype name: EmergencyCallData.Comment+xml

      Mandatory parameters: N/A

      Optional parameters: charset (indicates the character encoding of
      the contents)

      Encoding considerations: Uses XML, which can contain 8-bit
      characters, depending on the character encoding.  See Section 3.2
      of RFC 7303 [RFC7303].

      Security considerations: This content type is designed to carry a
      comment, which is a sub-category of additional data about an
      emergency call.  This data can contain personal information.
      Appropriate precautions are needed to limit unauthorized access,
      inappropriate disclosure to third parties, and eavesdropping of
      this information.  Please refer to Sections 9 and 10 for more
      information.

      Interoperability considerations: N/A

      Published specification: RFC 7852

      Applications that use this media type: Emergency Services

      Additional information:

         Magic Number: N/A

         File Extension: .xml

         Macintosh file type code: 'TEXT'

      Person and email address for further information:
      Hannes Tschofenig, Hannes.Tschofenig@gmx.net

      Intended usage: LIMITED USE

      Author: This specification is a work item of the IETF ECRIT
      working group, with mailing list address <ecrit@ietf.org>.

      Change controller: The IESG <iesg@ietf.org>









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11.5.  URN Sub-Namespace Registration

11.5.1.  Registration for urn:ietf:params:xml:ns:EmergencyCallData

   This section registers a new XML namespace, as per the guidelines in
   RFC 3688 [RFC3688].

   URI:  urn:ietf:params:xml:ns:EmergencyCallData

   Registrant Contact:  IETF, ECRIT working group, <ecrit@ietf.org>, as
      delegated by the IESG <iesg@ietf.org>.

   XML:

      BEGIN
      <?xml version="1.0"?>
      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
        "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
      <html xmlns="http://www.w3.org/1999/xhtml">
      <head>
        <meta http-equiv="content-type"
              content="text/html;charset=iso-8859-1"/>
        <title>Namespace for Additional Emergency Call Data</title>
      </head>
      <body>
        <h1>Namespace for Additional Data Related to an Emergency Call
           </h1>
      <p>See <a href="http://www.rfc-editor.org/rfc/rfc7852.txt">
         RFC 7852</a>.</p>
      </body>
      </html>
      END

11.5.2.  Registration for
         urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo

   This section registers a new XML namespace, as per the guidelines in
   RFC 3688 [RFC3688].

   URI:  urn:ietf:params:xml:ns:EmergencyCallData:ProviderInfo

   Registrant Contact:  IETF, ECRIT working group, <ecrit@ietf.org>, as
      delegated by the IESG <iesg@ietf.org>.








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   XML:

      BEGIN
      <?xml version="1.0"?>
      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
        "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
      <html xmlns="http://www.w3.org/1999/xhtml">
      <head>
        <meta http-equiv="content-type"
              content="text/html;charset=iso-8859-1"/>
        <title>Namespace for Additional Emergency Call Data:
               Data Provider Information</title>
      </head>
      <body>
        <h1>Namespace for Additional Data Related to an Emergency Call
           </h1>
        <h2>Data Provider Information</h2>
      <p>See <a href="http://www.rfc-editor.org/rfc/rfc7852.txt">
         RFC 7852</a>.</p>
      </body>
      </html>
      END

11.5.3.  Registration for
         urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo

   This section registers a new XML namespace, as per the guidelines in
   RFC 3688 [RFC3688].

   URI:  urn:ietf:params:xml:ns:EmergencyCallData:ServiceInfo

   Registrant Contact:  IETF, ECRIT working group, <ecrit@ietf.org>, as
      delegated by the IESG <iesg@ietf.org>.

   XML:

      BEGIN
      <?xml version="1.0"?>
      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
        "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
      <html xmlns="http://www.w3.org/1999/xhtml">
      <head>
        <meta http-equiv="content-type"
              content="text/html;charset=iso-8859-1"/>
        <title>Namespace for Additional Emergency Call Data:
               Service Information</title>
      </head>
      <body>



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        <h1>Namespace for Additional Data Related to an Emergency Call
           </h1>
        <h2>Service Information</h2>
      <p>See <a href="http://www.rfc-editor.org/rfc/rfc7852.txt">
         RFC 7852</a>.</p>
      </body>
      </html>
      END

11.5.4.  Registration for
         urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo

   This section registers a new XML namespace, as per the guidelines in
   RFC 3688 [RFC3688].

   URI:  urn:ietf:params:xml:ns:EmergencyCallData:DeviceInfo

   Registrant Contact:  IETF, ECRIT working group, <ecrit@ietf.org>, as
      delegated by the IESG <iesg@ietf.org>.

   XML:

      BEGIN
      <?xml version="1.0"?>
      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
        "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
      <html xmlns="http://www.w3.org/1999/xhtml">
      <head>
        <meta http-equiv="content-type"
              content="text/html;charset=iso-8859-1"/>
        <title>Namespace for Additional Emergency Call Data:
               Device Information</title>
      </head>
      <body>
        <h1>Namespace for Additional Data Related to an Emergency Call
           </h1>
        <h2>Device Information</h2>
      <p>See <a href="http://www.rfc-editor.org/rfc/rfc7852.txt">
         RFC 7852</a>.</p>
      </body>
      </html>
      END









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11.5.5.  Registration for
         urn:ietf:params:xml:ns:EmergencyCallData:SubscriberInfo

   This section registers a new XML namespace, as per the guidelines in
   RFC 3688 [RFC3688].

   URI:  urn:ietf:params:xml:ns:EmergencyCallData:SubscriberInfo

   Registrant Contact:  IETF, ECRIT working group, <ecrit@ietf.org>, as
      delegated by the IESG <iesg@ietf.org>.

   XML:

      BEGIN
      <?xml version="1.0"?>
      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
        "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
      <html xmlns="http://www.w3.org/1999/xhtml">
      <head>
        <meta http-equiv="content-type"
              content="text/html;charset=iso-8859-1"/>
        <title>Namespace for Additional Emergency Call Data:
               Owner/Subscriber Information</title>
      </head>
      <body>
        <h1>Namespace for Additional Data Related to an Emergency Call
           </h1>
        <h2> Owner/Subscriber Information</h2>
      <p>See <a href="http://www.rfc-editor.org/rfc/rfc7852.txt">
         RFC 7852</a>.</p>
      </body>
      </html>
      END

11.5.6.  Registration for
         urn:ietf:params:xml:ns:EmergencyCallData:Comment

   This section registers a new XML namespace, as per the guidelines in
   RFC 3688 [RFC3688].

   URI:  urn:ietf:params:xml:ns:EmergencyCallData:Comment

   Registrant Contact:  IETF, ECRIT working group, <ecrit@ietf.org>, as
      delegated by the IESG <iesg@ietf.org>.







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   XML:

      BEGIN
      <?xml version="1.0"?>
      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
        "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
      <html xmlns="http://www.w3.org/1999/xhtml">
      <head>
        <meta http-equiv="content-type"
              content="text/html;charset=iso-8859-1"/>
        <title>Namespace for Additional Emergency Call Data:Comment
           </title>
      </head>
      <body>
        <h1>Namespace for Additional Data Related to an Emergency Call
           </h1>
        <h2> Comment</h2>
      <p>See <a href="http://www.rfc-editor.org/rfc/rfc7852.txt">
         RFC 7852</a>.</p>
      </body>
      </html>
      END

11.6.  Schema Registrations

   This specification registers the following schemas, as per the
   guidelines in RFC 3688 [RFC3688].

      ID: EmergencyCallData
      URI: urn:ietf:params:xml:schema:EmergencyCallData
      Registrant Contact: IETF, ECRIT Working Group (ecrit@ietf.org), as
      delegated by the IESG (iesg@ietf.org).
      XML: The XML schema can be found in Section 8.6.

      ID: EmergencyCallData:ProviderInfo
      URI: urn:ietf:params:xml:schema:EmergencyCallData:ProviderInfo
      Registrant Contact: IETF, ECRIT working group (ecrit@ietf.org), as
      delegated by the IESG (iesg@ietf.org).
      XML: The XML schema can be found in Figure 19.

      ID: EmergencyCallData:ServiceInfo
      URI: urn:ietf:params:xml:schema:EmergencyCallData:ServiceInfo
      Registrant Contact: IETF, ECRIT working group (ecrit@ietf.org), as
      delegated by the IESG (iesg@ietf.org).
      XML: The XML schema can be found in Figure 20.






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      ID: EmergencyCallData:DeviceInfo
      URI: urn:ietf:params:xml:schema:EmergencyCallData:DeviceInfo
      Registrant Contact: IETF, ECRIT working group (ecrit@ietf.org), as
      delegated by the IESG (iesg@ietf.org).

      XML: The XML schema can be found in Figure 21.

      ID: EmergencyCallData:SubscriberInfo
      URI: urn:ietf:params:xml:schema:EmergencyCallData:SubscriberInfo
      Registrant Contact: IETF, ECRIT working group (ecrit@ietf.org), as
      delegated by the IESG (iesg@ietf.org).
      XML: The XML schema can be found in Section 8.4.

      ID: EmergencyCallData:Comment
      URI: urn:ietf:params:xml:schema:EmergencyCallData:Comment
      Registrant Contact: IETF, ECRIT working group (ecrit@ietf.org), as
      delegated by the IESG (iesg@ietf.org).
      XML: The XML schema can be found in Section 8.5.

      ID: vcard-4.0
      URI: urn:ietf:params:xml:ns:vcard-4.0
      Registrant Contact: IETF, ECRIT Working Group (ecrit@ietf.org), as
      delegated by the IESG (iesg@ietf.org).
      XML: The XML schema can be found in Appendix A.

11.7.  vCard Parameter Value Registration

   This document registers a new value in the "vCard Parameter Values"
   registry as defined by [RFC6350] with the following template:

   Value:  main-number

   Purpose:  The main telephone number, typically of an enterprise, as
      opposed to a direct-dial number of an individual employee

   Conformance:  This value can be used with the 'TYPE' parameter
      applied on the 'TEL' property

   Example(s):  TEL;VALUE=uri;TYPE="main,voice";PREF=1:tel:+1-418-656-90
      00











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12.  References

12.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC2392]  Levinson, E., "Content-ID and Message-ID Uniform Resource
              Locators", RFC 2392, DOI 10.17487/RFC2392, August 1998,
              <http://www.rfc-editor.org/info/rfc2392>.

   [RFC3204]  Zimmerer, E., Peterson, J., Vemuri, A., Ong, L., Audet,
              F., Watson, M., and M. Zonoun, "MIME media types for ISUP
              and QSIG Objects", RFC 3204, DOI 10.17487/RFC3204,
              December 2001, <http://www.rfc-editor.org/info/rfc3204>.

   [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
              A., Peterson, J., Sparks, R., Handley, M., and E.
              Schooler, "SIP: Session Initiation Protocol", RFC 3261,
              DOI 10.17487/RFC3261, June 2002,
              <http://www.rfc-editor.org/info/rfc3261>.

   [RFC3459]  Burger, E., "Critical Content Multi-purpose Internet Mail
              Extensions (MIME) Parameter", RFC 3459,
              DOI 10.17487/RFC3459, January 2003,
              <http://www.rfc-editor.org/info/rfc3459>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <http://www.rfc-editor.org/info/rfc3688>.

   [RFC3966]  Schulzrinne, H., "The tel URI for Telephone Numbers",
              RFC 3966, DOI 10.17487/RFC3966, December 2004,
              <http://www.rfc-editor.org/info/rfc3966>.

   [RFC4119]  Peterson, J., "A Presence-based GEOPRIV Location Object
              Format", RFC 4119, DOI 10.17487/RFC4119, December 2005,
              <http://www.rfc-editor.org/info/rfc4119>.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              DOI 10.17487/RFC5226, May 2008,
              <http://www.rfc-editor.org/info/rfc5226>.






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   [RFC5322]  Resnick, P., Ed., "Internet Message Format", RFC 5322,
              DOI 10.17487/RFC5322, October 2008,
              <http://www.rfc-editor.org/info/rfc5322>.

   [RFC5621]  Camarillo, G., "Message Body Handling in the Session
              Initiation Protocol (SIP)", RFC 5621,
              DOI 10.17487/RFC5621, September 2009,
              <http://www.rfc-editor.org/info/rfc5621>.

   [RFC5646]  Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
              Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
              September 2009, <http://www.rfc-editor.org/info/rfc5646>.

   [RFC6350]  Perreault, S., "vCard Format Specification", RFC 6350,
              DOI 10.17487/RFC6350, August 2011,
              <http://www.rfc-editor.org/info/rfc6350>.

   [RFC6351]  Perreault, S., "xCard: vCard XML Representation",
              RFC 6351, DOI 10.17487/RFC6351, August 2011,
              <http://www.rfc-editor.org/info/rfc6351>.

   [RFC6838]  Freed, N., Klensin, J., and T. Hansen, "Media Type
              Specifications and Registration Procedures", BCP 13,
              RFC 6838, DOI 10.17487/RFC6838, January 2013,
              <http://www.rfc-editor.org/info/rfc6838>.

   [RFC7303]  Thompson, H. and C. Lilley, "XML Media Types", RFC 7303,
              DOI 10.17487/RFC7303, July 2014,
              <http://www.rfc-editor.org/info/rfc7303>.

12.2.  Informative References

   [ECRIT-WG-wiki]
              IETF ECRIT WG Wiki, "Additional Data Examples", July 2015,
              <http://tools.ietf.org/wg/ecrit/trac/attachment/wiki/
              WikiStart/additional-data-examples.zip>.

   [Err3047]  RFC Errata, Erratum ID 3047, RFC 6351.

   [HUMAN-LANG]
              Gellens, R., "Negotiating Human Language in Real-Time
              Communications", Work in Progress, draft-ietf-slim-
              negotiating-human-language-04, July 2016.

   [IANA-XML-Schemas]
              IANA, "IETF XML Registry",
              <http://www.iana.org/assignments/xml-registry>.




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   [IEEE-1512-2006]
              IEEE, "IEEE Standard for Common Incident Management
              Message Sets for Use by Emergency Management Centers",
              IEEE Std 1512-2006, DOI 10.1109/IEEESTD.2006.224678,
              August 2006, <https://standards.ieee.org/findstds/
              standard/1512-2006.html>.

   [LanguageSubtagRegistry]
              IANA, "Language Subtag Registry",
              <http://www.iana.org/assignments/
              language-subtag-registry>.

   [LERG]     Telcordia Technologies, Inc., "LERG Routing Guide", ANI
              II Digits Definitions, June 2015.

   [NANP]     North American Numbering Plan Administration (NANPA), "ANI
              II Digits Assignments", September 2015,
              <http://nanpa.com/number_resource_info/
              ani_ii_assignments.html>.

   [nc911]    North Carolina 911 Board, "Wireless 911 for
              Telecommunicators", January 2009,
              <https://www.nc911.nc.gov/pdf/
              A_TelecommunicatorReference.pdf>.

   [NENA-02-010]
              National Emergency Number Association (NENA), "NENA
              Standard Data Formats for 9-1-1 Data Exchange & GIS
              Mapping", NENA-02-010, Version 9, December 2010,
              <http://www.nena.org>.

   [RFC3325]  Jennings, C., Peterson, J., and M. Watson, "Private
              Extensions to the Session Initiation Protocol (SIP) for
              Asserted Identity within Trusted Networks", RFC 3325,
              DOI 10.17487/RFC3325, November 2002,
              <http://www.rfc-editor.org/info/rfc3325>.

   [RFC3840]  Rosenberg, J., Schulzrinne, H., and P. Kyzivat,
              "Indicating User Agent Capabilities in the Session
              Initiation Protocol (SIP)", RFC 3840,
              DOI 10.17487/RFC3840, August 2004,
              <http://www.rfc-editor.org/info/rfc3840>.

   [RFC5012]  Schulzrinne, H. and R. Marshall, Ed., "Requirements for
              Emergency Context Resolution with Internet Technologies",
              RFC 5012, DOI 10.17487/RFC5012, January 2008,
              <http://www.rfc-editor.org/info/rfc5012>.




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   [RFC5139]  Thomson, M. and J. Winterbottom, "Revised Civic Location
              Format for Presence Information Data Format Location
              Object (PIDF-LO)", RFC 5139, DOI 10.17487/RFC5139,
              February 2008, <http://www.rfc-editor.org/info/rfc5139>.

   [RFC5491]  Winterbottom, J., Thomson, M., and H. Tschofenig, "GEOPRIV
              Presence Information Data Format Location Object (PIDF-LO)
              Usage Clarification, Considerations, and Recommendations",
              RFC 5491, DOI 10.17487/RFC5491, March 2009,
              <http://www.rfc-editor.org/info/rfc5491>.

   [RFC5582]  Schulzrinne, H., "Location-to-URL Mapping Architecture and
              Framework", RFC 5582, DOI 10.17487/RFC5582, September
              2009, <http://www.rfc-editor.org/info/rfc5582>.

   [RFC5962]  Schulzrinne, H., Singh, V., Tschofenig, H., and M.
              Thomson, "Dynamic Extensions to the Presence Information
              Data Format Location Object (PIDF-LO)", RFC 5962,
              DOI 10.17487/RFC5962, September 2010,
              <http://www.rfc-editor.org/info/rfc5962>.

   [RFC5985]  Barnes, M., Ed., "HTTP-Enabled Location Delivery (HELD)",
              RFC 5985, DOI 10.17487/RFC5985, September 2010,
              <http://www.rfc-editor.org/info/rfc5985>.

   [RFC6443]  Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,
              "Framework for Emergency Calling Using Internet
              Multimedia", RFC 6443, DOI 10.17487/RFC6443, December
              2011, <http://www.rfc-editor.org/info/rfc6443>.

   [RFC6698]  Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
              of Named Entities (DANE) Transport Layer Security (TLS)
              Protocol: TLSA", RFC 6698, DOI 10.17487/RFC6698, August
              2012, <http://www.rfc-editor.org/info/rfc6698>.

   [RFC6848]  Winterbottom, J., Thomson, M., Barnes, R., Rosen, B., and
              R. George, "Specifying Civic Address Extensions in the
              Presence Information Data Format Location Object (PIDF-
              LO)", RFC 6848, DOI 10.17487/RFC6848, January 2013,
              <http://www.rfc-editor.org/info/rfc6848>.

   [RFC6881]  Rosen, B. and J. Polk, "Best Current Practice for
              Communications Services in Support of Emergency Calling",
              BCP 181, RFC 6881, DOI 10.17487/RFC6881, March 2013,
              <http://www.rfc-editor.org/info/rfc6881>.






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   [RFC6973]  Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
              Morris, J., Hansen, M., and R. Smith, "Privacy
              Considerations for Internet Protocols", RFC 6973,
              DOI 10.17487/RFC6973, July 2013,
              <http://www.rfc-editor.org/info/rfc6973>.

   [RFC7035]  Thomson, M., Rosen, B., Stanley, D., Bajko, G., and A.
              Thomson, "Relative Location Representation", RFC 7035,
              DOI 10.17487/RFC7035, October 2013,
              <http://www.rfc-editor.org/info/rfc7035>.

   [RFC7090]  Schulzrinne, H., Tschofenig, H., Holmberg, C., and M.
              Patel, "Public Safety Answering Point (PSAP) Callback",
              RFC 7090, DOI 10.17487/RFC7090, April 2014,
              <http://www.rfc-editor.org/info/rfc7090>.

   [RFC7525]  Sheffer, Y., Holz, R., and P. Saint-Andre,
              "Recommendations for Secure Use of Transport Layer
              Security (TLS) and Datagram Transport Layer Security
              (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
              2015, <http://www.rfc-editor.org/info/rfc7525>.






























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Appendix A.  XML Schema for vCard/xCard

   This section contains the vCard/xCard XML schema version of the Relax
   NG schema defined in RFC 6351 [RFC6351] for use with the XML schemas
   defined in this document.  In addition to mapping the Relax NG schema
   to an XML schema, this specification applies an erratum raised for
   RFC 6351 regarding the type definition; see RFC Erratum ID 3047
   [Err3047].

   <?xml version="1.0" encoding="UTF-8"?>
   <xs:schema
     targetNamespace="urn:ietf:params:xml:ns:vcard-4.0"
     xmlns:xs="http://www.w3.org/2001/XMLSchema"
     xmlns:ns1="urn:ietf:params:xml:ns:vcard-4.0"
     elementFormDefault="qualified">
     <!--
       3.3
       iana-token = xsd:string { pattern = "[a-zA-Z0-9-]+" }
       x-name = xsd:string { pattern = "x-[a-zA-Z0-9-]+" }
     -->
     <xs:simpleType name="iana-token">
       <xs:annotation>
         <xs:documentation>Section 3.3: vCard Format Specification
         </xs:documentation>
       </xs:annotation>
       <xs:restriction base="xs:string"/>
     </xs:simpleType>
     <xs:simpleType name="x-name">
       <xs:restriction base="xs:string"/>
     </xs:simpleType>
     <!--
       4.1
     -->
     <xs:element name="text" type="xs:string"/>
     <xs:group name="value-text-list">
       <xs:sequence>
         <xs:element ref="ns1:text" maxOccurs="unbounded"/>
       </xs:sequence>
     </xs:group>
     <!-- 4.2 -->
     <xs:element name="uri" type="xs:anyURI"/>
     <!-- 4.3.1 -->
     <xs:element name="date"
         substitutionGroup="ns1:value-date-and-or-time">
       <xs:simpleType>
         <xs:restriction base="xs:string">
           <xs:pattern
              value="\d{8}|\d{4}-\d\d|--\d\d(\d\d)?|---\d\d"/>



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         </xs:restriction>
       </xs:simpleType>
     </xs:element>
     <!-- 4.3.2 -->
     <xs:element name="time"
         substitutionGroup="ns1:value-date-and-or-time">
       <xs:simpleType>
         <xs:restriction base="xs:string">
           <xs:pattern value=
     "(\d\d(\d\d(\d\d)?)?|-\d\d(\d\d?)|--\d\d)(Z|[+\-]\d\d(\d\d)?)?"/>
         </xs:restriction>
       </xs:simpleType>
     </xs:element>
     <!-- 4.3.3 -->
     <xs:element name="date-time"
       substitutionGroup="ns1:value-date-and-or-time">
       <xs:simpleType>
         <xs:restriction base="xs:string">
           <xs:pattern value=
     "(\d{8}|--\d{4}|---\d\d)T\d\d(\d\d(\d\d)?)?(Z|[+\-]\d\d(\d\d)?)?"/>
         </xs:restriction>
       </xs:simpleType>
     </xs:element>
     <!-- 4.3.4 -->
     <xs:element name="value-date-and-or-time" abstract="true"/>
     <!-- 4.3.5 -->
     <xs:complexType name="value-timestamp">
       <xs:sequence>
         <xs:element ref="ns1:timestamp"/>
       </xs:sequence>
     </xs:complexType>
     <xs:element name="timestamp">
       <xs:simpleType>
         <xs:restriction base="xs:string">
           <xs:pattern value="\d{8}T\d{6}(Z|[+\-]\d\d(\d\d)?)?"/>
         </xs:restriction>
       </xs:simpleType>
     </xs:element>
     <!-- 4.4 -->
     <xs:element name="boolean" type="xs:boolean"/>
     <!-- 4.5 -->
     <xs:element name="integer" type="xs:integer"/>
     <!-- 4.6 -->
     <xs:element name="float" type="xs:float"/>
     <!-- 4.7 -->
     <xs:element name="utc-offset">
       <xs:simpleType>
         <xs:restriction base="xs:string">



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           <xs:pattern value="[+\-]\d\d(\d\d)?"/>
         </xs:restriction>
       </xs:simpleType>
     </xs:element>
     <!-- 4.8 -->
     <xs:element name="language-tag">
       <xs:simpleType>
         <xs:restriction base="xs:string">
           <xs:pattern value=
   "([a-z]{2,3}((-[a-z]{3}){0,3})?|[a-z]{4,8})(-[a-z]{4})?
   (-([a-z]{2}|\d{3}))?(-([0-9a-z]{5,8}|\d[0-9a-z]{3}))*
   (-[0-9a-wyz](-[0-9a-z]{2,8})+)*(-x(-[0-9a-z]{1,8})+)?
   |x(-[0-9a-z]{1,8})+|[a-z]{1,3}(-[0-9a-z]{2,8}){1,2}"/>
         </xs:restriction>
       </xs:simpleType>
     </xs:element>
     <!--
       5.1
     -->
     <xs:group name="param-language">
       <xs:annotation>
         <xs:documentation>Section 5: Parameters</xs:documentation>
       </xs:annotation>
       <xs:sequence>
         <xs:element ref="ns1:language" minOccurs="0"/>
       </xs:sequence>
     </xs:group>
     <xs:element name="language">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:language-tag"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 5.2 -->
     <xs:group name="param-pref">
       <xs:sequence>
         <xs:element ref="ns1:pref" minOccurs="0"/>
       </xs:sequence>
     </xs:group>
     <xs:element name="pref">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="integer">
             <xs:simpleType>
               <xs:restriction base="xs:integer">
                 <xs:minInclusive value="1"/>
                 <xs:maxInclusive value="100"/>



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               </xs:restriction>
             </xs:simpleType>
           </xs:element>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 5.4 -->
     <xs:group name="param-altid">
       <xs:sequence>
         <xs:element ref="ns1:altid" minOccurs="0"/>
       </xs:sequence>
     </xs:group>
     <xs:element name="altid">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 5.5 -->
     <xs:group name="param-pid">
       <xs:sequence>
         <xs:element ref="ns1:pid" minOccurs="0"/>
       </xs:sequence>
     </xs:group>
     <xs:element name="pid">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="text" maxOccurs="unbounded">
             <xs:simpleType>
               <xs:restriction base="xs:string">
                 <xs:pattern value="\d+(\.\d+)?"/>
               </xs:restriction>
             </xs:simpleType>
           </xs:element>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 5.6 -->
     <xs:group name="param-type">
       <xs:sequence>
         <xs:element ref="ns1:type" minOccurs="0"/>
       </xs:sequence>
     </xs:group>
     <xs:element name="type">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="text" maxOccurs="unbounded">



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             <xs:simpleType>
               <xs:restriction base="xs:token">
                 <xs:enumeration value="work"/>
                 <xs:enumeration value="home"/>
               </xs:restriction>
             </xs:simpleType>
           </xs:element>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 5.7 -->
     <xs:group name="param-mediatype">
       <xs:sequence>
         <xs:element ref="ns1:mediatype" minOccurs="0"/>
       </xs:sequence>
     </xs:group>
     <xs:element name="mediatype">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 5.8 -->
     <xs:group name="param-calscale">
       <xs:sequence>
         <xs:element ref="ns1:calscale" minOccurs="0"/>
       </xs:sequence>
     </xs:group>
     <xs:element name="calscale">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="text">
             <xs:simpleType>
               <xs:restriction base="xs:token">
                 <xs:enumeration value="gregorian"/>
               </xs:restriction>
             </xs:simpleType>
           </xs:element>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 5.9 -->
     <xs:group name="param-sort-as">
       <xs:sequence>
         <xs:element ref="ns1:sort-as" minOccurs="0"/>
       </xs:sequence>
     </xs:group>



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     <xs:element name="sort-as">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:text" maxOccurs="unbounded"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 5.10 -->
     <xs:group name="param-geo">
       <xs:sequence>
         <xs:element name="geo" minOccurs="0">
           <xs:complexType>
             <xs:sequence>
               <xs:element ref="ns1:uri"/>
             </xs:sequence>
           </xs:complexType>
         </xs:element>
       </xs:sequence>
     </xs:group>
     <!-- 5.11 -->
     <xs:group name="param-tz">
       <xs:sequence>
         <xs:element name="tz" minOccurs="0">
           <xs:complexType>
             <xs:choice>
               <xs:element ref="ns1:text"/>
               <xs:element ref="ns1:uri"/>
             </xs:choice>
           </xs:complexType>
         </xs:element>
       </xs:sequence>
     </xs:group>
     <!--
       6.1.3
     -->
     <xs:element name="source">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>



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           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.1.4 -->
     <xs:element name="kind">
       <xs:complexType>
         <xs:sequence>
           <xs:annotation>
             <xs:documentation>
               The text value must be one of: individual, group, org,
         location or a ns1:x-name or a ns1:iana-token value
             </xs:documentation>
           </xs:annotation>
           <xs:element name="text" type="xs:token"
                 minOccurs="1" maxOccurs="1"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.2.1 -->
     <xs:element name="fn">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.2.2 -->
     <xs:element name="n">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-sort-as"/>
                 <xs:group ref="ns1:param-altid"/>



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               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:surname"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:given"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:additional"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:prefix"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:suffix"
             minOccurs="0" maxOccurs="unbounded"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <xs:element name="surname" type="xs:string"/>
     <xs:element name="given" type="xs:string"/>
     <xs:element name="additional" type="xs:string"/>
     <xs:element name="prefix" type="xs:string"/>
     <xs:element name="suffix" type="xs:string"/>
     <!-- 6.2.3 -->
     <xs:element name="nickname">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:group ref="ns1:value-text-list"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.2.4 -->
     <xs:element name="photo">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>



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                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.2.5 -->
     <xs:element name="bday">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-calscale"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:choice>
             <xs:element ref="ns1:value-date-and-or-time"/>
             <xs:element ref="ns1:text"/>
           </xs:choice>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.2.6 -->
     <xs:element name="anniversary">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-calscale"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:choice>
             <xs:element ref="ns1:value-date-and-or-time"/>
             <xs:element ref="ns1:text"/>
           </xs:choice>
         </xs:sequence>
       </xs:complexType>



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     </xs:element>
     <!-- 6.2.7 -->
     <xs:element name="gender">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:sex"/>
           <xs:element ref="ns1:identity" minOccurs="0"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <xs:element name="sex">
       <xs:simpleType>
         <xs:restriction base="xs:token">
           <xs:enumeration value=""/>
           <xs:enumeration value="M"/>
           <xs:enumeration value="F"/>
           <xs:enumeration value="O"/>
           <xs:enumeration value="N"/>
           <xs:enumeration value="U"/>
         </xs:restriction>
       </xs:simpleType>
     </xs:element>
     <xs:element name="identity" type="xs:string"/>
     <!-- 6.3.1 -->
     <xs:group name="param-label">
       <xs:sequence>
         <xs:element ref="ns1:label" minOccurs="0"/>
       </xs:sequence>
     </xs:group>
     <xs:element name="label">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <xs:element name="adr">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-geo"/>



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                 <xs:group ref="ns1:param-tz"/>
                 <xs:group ref="ns1:param-label"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:pobox"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:ext"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:street"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:locality"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:region"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:code"
             minOccurs="0" maxOccurs="unbounded"/>
           <xs:element ref="ns1:country"
             minOccurs="0" maxOccurs="unbounded"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <xs:element name="pobox" type="xs:string"/>
     <xs:element name="ext" type="xs:string"/>
     <xs:element name="street" type="xs:string"/>
     <xs:element name="locality" type="xs:string"/>
     <xs:element name="region" type="xs:string"/>
     <xs:element name="code" type="xs:string"/>
     <xs:element name="country" type="xs:string"/>
     <!-- 6.4.1 -->
     <xs:element name="tel">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"
                   minOccurs="0"/>
                 <xs:group ref="ns1:param-pid"
                   minOccurs="0"/>
                 <xs:group ref="ns1:param-pref"
                   minOccurs="0"/>
                 <xs:element name="type" minOccurs="0">
                   <xs:complexType>
                     <xs:sequence>
                       <xs:element name="text"
                         type="xs:string"
                         maxOccurs="unbounded">



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                       </xs:element>
                     </xs:sequence>
                   </xs:complexType>
                 </xs:element>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:choice>
             <xs:element ref="ns1:text"/>
             <xs:element ref="ns1:uri"/>
           </xs:choice>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.4.2 -->
     <xs:element name="email">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.4.3 -->
     <xs:element name="impp">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>



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           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.4.4 -->
     <xs:element name="lang">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:language-tag"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.5.1 -->
     <xs:group name="property-tz">
       <xs:sequence>
         <xs:element name="tz">
           <xs:complexType>
             <xs:sequence>
               <xs:element name="parameters" minOccurs="0">
                 <xs:complexType>
                   <xs:sequence>
                     <xs:group ref="ns1:param-altid"/>
                     <xs:group ref="ns1:param-pid"/>
                     <xs:group ref="ns1:param-pref"/>
                     <xs:group ref="ns1:param-type"/>
                     <xs:group
                     ref="ns1:param-mediatype"/>
                   </xs:sequence>
                 </xs:complexType>
               </xs:element>
               <xs:choice>
                 <xs:element ref="ns1:text"/>
                 <xs:element ref="ns1:uri"/>
                 <xs:element ref="ns1:utc-offset"/>
               </xs:choice>
             </xs:sequence>
           </xs:complexType>
         </xs:element>



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       </xs:sequence>
     </xs:group>
     <!-- 6.5.2 -->
     <xs:group name="property-geo">
       <xs:sequence>
         <xs:element name="geo">
           <xs:complexType>
             <xs:sequence>
               <xs:element name="parameters" minOccurs="0">
                 <xs:complexType>
                   <xs:sequence>
                     <xs:group ref="ns1:param-altid"/>
                     <xs:group ref="ns1:param-pid"/>
                     <xs:group ref="ns1:param-pref"/>
                     <xs:group ref="ns1:param-type"/>
                     <xs:group
                     ref="ns1:param-mediatype"/>
                   </xs:sequence>
                 </xs:complexType>
               </xs:element>
               <xs:element ref="ns1:uri"/>
             </xs:sequence>
           </xs:complexType>
         </xs:element>
       </xs:sequence>
     </xs:group>
     <!-- 6.6.1 -->
     <xs:element name="title">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.6.2 -->
     <xs:element name="role">
       <xs:complexType>



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         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.6.3 -->
     <xs:element name="logo">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.6.4 -->
     <xs:element name="org">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>



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                 <xs:group ref="ns1:param-sort-as"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:group ref="ns1:value-text-list"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.6.5 -->
     <xs:element name="member">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.6.6 -->
     <xs:element name="related">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:element name="type" minOccurs="0">
                   <xs:complexType>
                     <xs:sequence>
                       <xs:element name="text" maxOccurs="unbounded">
                         <xs:simpleType>
                           <xs:restriction base="xs:token">
                             <xs:enumeration value="work"/>
                             <xs:enumeration value="home"/>
                             <xs:enumeration value="contact"/>
                             <xs:enumeration value="acquaintance"/>
                             <xs:enumeration value="friend"/>
                             <xs:enumeration value="met"/>



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                             <xs:enumeration value="co-worker"/>
                             <xs:enumeration value="colleague"/>
                             <xs:enumeration value="co-resident"/>
                             <xs:enumeration value="neighbor"/>
                             <xs:enumeration value="child"/>
                             <xs:enumeration value="parent"/>
                             <xs:enumeration value="sibling"/>
                             <xs:enumeration value="spouse"/>
                             <xs:enumeration value="kin"/>
                             <xs:enumeration value="muse"/>
                             <xs:enumeration value="crush"/>
                             <xs:enumeration value="date"/>
                             <xs:enumeration value="sweetheart"/>
                             <xs:enumeration value="me"/>
                             <xs:enumeration value="agent"/>
                             <xs:enumeration value="emergency"/>
                           </xs:restriction>
                         </xs:simpleType>
                       </xs:element>
                     </xs:sequence>
                   </xs:complexType>
                 </xs:element>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:choice>
             <xs:element ref="ns1:uri"/>
             <xs:element ref="ns1:text"/>
           </xs:choice>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.7.1 -->
     <xs:element name="categories">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:group ref="ns1:value-text-list"/>



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         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.7.2 -->
     <xs:element name="note">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.7.3 -->
     <xs:element name="prodid">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:text"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.7.4 -->
     <xs:element name="rev" type="ns1:value-timestamp"/>
     <!-- 6.7.5 -->
     <xs:element name="sound">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-language"/>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>



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           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.7.6 -->
     <xs:element name="uid">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.7.7 -->
     <xs:element name="clientpidmap">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:sourceid"/>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <xs:element name="sourceid" type="xs:positiveInteger"/>
     <!-- 6.7.8 -->
     <xs:element name="url">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.8.1 -->
     <xs:element name="key">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>



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                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:choice>
             <xs:element ref="ns1:uri"/>
             <xs:element ref="ns1:text"/>
           </xs:choice>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.9.1 -->
     <xs:element name="fburl">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.9.2 -->
     <xs:element name="caladruri">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>



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           </xs:element>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- 6.9.3 -->
     <xs:element name="caluri">
       <xs:complexType>
         <xs:sequence>
           <xs:element name="parameters" minOccurs="0">
             <xs:complexType>
               <xs:sequence>
                 <xs:group ref="ns1:param-altid"/>
                 <xs:group ref="ns1:param-pid"/>
                 <xs:group ref="ns1:param-pref"/>
                 <xs:group ref="ns1:param-type"/>
                 <xs:group ref="ns1:param-mediatype"/>
               </xs:sequence>
             </xs:complexType>
           </xs:element>
           <xs:element ref="ns1:uri"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <!-- Top-level grammar -->
     <xs:group name="property">
       <xs:sequence>
         <xs:element ref="ns1:adr" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:anniversary" minOccurs="0"
           maxOccurs="1"/>
         <xs:element ref="ns1:bday" minOccurs="0"
           maxOccurs="1"/>
         <xs:element ref="ns1:caladruri" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:caluri" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:categories" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:clientpidmap" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:email" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:fburl" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:fn" minOccurs="1"
           maxOccurs="unbounded"/>
         <xs:group ref="ns1:property-geo" minOccurs="0"



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           maxOccurs="unbounded"/>
         <xs:element ref="ns1:impp" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:key" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:kind" minOccurs="0"
           maxOccurs="1"/>
         <xs:element ref="ns1:lang" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:logo" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:member" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:n" minOccurs="0"
           maxOccurs="1"/>
         <xs:element ref="ns1:nickname" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:note" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:org" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:photo" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:prodid" minOccurs="0"
           maxOccurs="1"/>
         <xs:element ref="ns1:related" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:rev" minOccurs="0"
           maxOccurs="1"/>
         <xs:element ref="ns1:role" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:gender" minOccurs="0"
           maxOccurs="1"/>
         <xs:element ref="ns1:sound" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:source" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:tel" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:title" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:group ref="ns1:property-tz" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:element ref="ns1:uid" minOccurs="0"
           maxOccurs="1"/>
         <xs:element ref="ns1:url" minOccurs="0"
           maxOccurs="unbounded"/>
       </xs:sequence>



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     </xs:group>
     <xs:element name="vcards">
       <xs:complexType>
         <xs:sequence>
           <xs:element ref="ns1:vcard" maxOccurs="unbounded"/>
         </xs:sequence>
       </xs:complexType>
     </xs:element>
     <xs:complexType name="vcardType">
       <xs:sequence>
         <xs:group ref="ns1:property"/>
         <xs:element ref="ns1:group" minOccurs="0"
           maxOccurs="unbounded"/>
         <xs:any namespace="##other" processContents="lax"
           minOccurs="0" maxOccurs="unbounded"/>
       </xs:sequence>
     </xs:complexType>
     <xs:element name="vcard" type="ns1:vcardType"/>
     <xs:element name="group">
       <xs:complexType>
         <xs:group ref="ns1:property"/>
         <xs:attribute name="name" use="required"/>
       </xs:complexType>
     </xs:element>
   </xs:schema>

Appendix B.  XML Validation

   This document defines a number of XML schemas and contains various
   examples.  Extracting the XML and validating the examples against the
   schemas can be challenging, especially due to the formatting
   limitations introduced by IETF RFCs.  For those readers who copy the
   XML schemas and examples directly from this document, please consider
   that errors might be introduced due to line breaks and extra
   whitespaces in the regular expressions contained in the vCard schema
   in Appendix A.  To validate the PIDF-LO from Figure 18, it is also
   necessary to consult the referenced RFCs and copy the schemas
   necessary for successful validation.

   The XML schemas found in this document include a 'SchemaLocation'
   attribute.  Depending on the location of the downloaded schema files,
   you may need to adjust this schema location or configure your XML
   editor to point to the location.

   For the convenience of the reader, the schemas are available at
   [IANA-XML-Schemas], and the XML examples are available at the IETF
   ECRIT working group wiki page [ECRIT-WG-wiki].




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Acknowledgments

   This work was originally started in NENA and has benefited from a
   large number of participants involved in NENA standardization
   efforts, originally in the Long Term Definition working group, the
   Data Technical Committee, and most recently in the Additional Data
   working group.  The authors are grateful for the initial work and
   extended comments provided by many NENA participants, including
   Delaine Arnold, Marc Berryman, Guy Caron, Brian Dupras, Mark
   Fletcher, James Leyerle, Kathy McMahon, Christian Militeau, Ira
   Pyles, Matt Serra, and Robert (Bob) Sherry.  Amursana Khiyod, Robert
   Sherry, Frank Rahoi, Scott Ross, and Tom Klepetka provided valuable
   feedback regarding the vCard/xCard use in this specification.

   We would also like to thank Paul Kyzivat, Gunnar Hellstrom, Martin
   Thomson, Keith Drage, Laura Liess, Chris Santer, Barbara Stark, Chris
   Santer, Archie Cobbs, Magnus Nystrom, Stephen Farrell, Amanda Baber,
   Dan Banks, Andrew Newton, Philip Reichl, and Francis Dupont for their
   review comments.  Alissa Cooper, Guy Caron, Ben Campbell, and Barry
   Leiba deserve special mention for their detailed and extensive review
   comments, which were very helpful and appreciated.






























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Authors' Addresses

   Randall Gellens
   San Diego, CA  92121
   United States

   Email: rg+ietf@randy.pensive.org


   Brian Rosen
   NeuStar
   470 Conrad Dr.
   Mars, PA  16046
   United States

   Phone: +1 724 382 1051
   Email: br@brianrosen.net


   Hannes Tschofenig
   Hall in Tirol  6060
   Austria

   Email: Hannes.tschofenig@gmx.net
   URI:   http://www.tschofenig.priv.at


   Roger Marshall
   TeleCommunication Systems, Inc.
   2401 Elliott Avenue
   Seattle, WA  98121
   United States

   Phone: +1 206 792 2424
   Email: rmarshall@telecomsys.com
   URI:   http://www.telecomsys.com


   James Winterbottom
   Winterb Consulting Services
   Gwynneville, NSW  2500
   Australia

   Phone: +61 448 266004
   Email: a.james.winterbottom@gmail.com






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