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JSContact: A JSON representation of contact data
draft-ietf-calext-jscontact-07

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 9553.
Authors Robert Stepanek , Mario Loffredo
Last updated 2023-03-03 (Latest revision 2023-01-10)
Replaces draft-ietf-jmap-jscontact, draft-stepanek-jscontact
Replaced by draft-ietf-jmap-jscontact
RFC stream Internet Engineering Task Force (IETF)
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Reviews
Additional resources Mailing list discussion
Stream WG state Submitted to IESG for Publication
Document shepherd Daniel Migault
Shepherd write-up Show Last changed 2023-01-10
IESG IESG state Became RFC 9553 (Proposed Standard)
Consensus boilerplate Yes
Telechat date (None)
Responsible AD Francesca Palombini
Send notices to mglt.ietf@gmail.com
IANA IANA review state IANA - Review Needed
draft-ietf-calext-jscontact-07
Calendaring Extensions                                       R. Stepanek
Internet-Draft                                                  Fastmail
Intended status: Standards Track                             M. Loffredo
Expires: 14 July 2023                                            IIT-CNR
                                                         10 January 2023

            JSContact: A JSON representation of contact data
                     draft-ietf-calext-jscontact-07

Abstract

   This specification defines a data model and JSON representation of
   contact card information that can be used for data storage and
   exchange in address book or directory applications.  It aims to be an
   alternative to the vCard data format and to be unambiguous,
   extendable and simple to process.  In contrast to the JSON-based
   jCard format, it is not a direct mapping from the vCard data model
   and expands semantics where appropriate.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 14 July 2023.

Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  Relation to the xCard and jCard formats . . . . . . . . .   5
     1.2.  Notational Conventions  . . . . . . . . . . . . . . . . .   5
     1.3.  ABNF Notations  . . . . . . . . . . . . . . . . . . . . .   5
     1.4.  Type Signatures . . . . . . . . . . . . . . . . . . . . .   5
     1.5.  Data types  . . . . . . . . . . . . . . . . . . . . . . .   6
       1.5.1.  Id  . . . . . . . . . . . . . . . . . . . . . . . . .   6
       1.5.2.  Int and UnsignedInt . . . . . . . . . . . . . . . . .   6
       1.5.3.  PatchObject . . . . . . . . . . . . . . . . . . . . .   7
       1.5.4.  Resource  . . . . . . . . . . . . . . . . . . . . . .   8
       1.5.5.  UTCDateTime . . . . . . . . . . . . . . . . . . . . .   8
     1.6.  Common properties . . . . . . . . . . . . . . . . . . . .   9
       1.6.1.  The contexts property . . . . . . . . . . . . . . . .   9
       1.6.2.  The label property  . . . . . . . . . . . . . . . . .   9
       1.6.3.  The pref property . . . . . . . . . . . . . . . . . .   9
     1.7.  Versioning  . . . . . . . . . . . . . . . . . . . . . . .  10
       1.7.1.  Version Scheme  . . . . . . . . . . . . . . . . . . .  10
       1.7.2.  Version Updates . . . . . . . . . . . . . . . . . . .  11
     1.8.  Validating JSContact Properties . . . . . . . . . . . . .  11
       1.8.1.  IANA-registered Properties  . . . . . . . . . . . . .  11
       1.8.2.  Unknown Properties  . . . . . . . . . . . . . . . . .  12
     1.9.  Vendor-Specific Extensions  . . . . . . . . . . . . . . .  12
       1.9.1.  Vendor-specific Properties  . . . . . . . . . . . . .  12
       1.9.2.  Vendor-specific Values  . . . . . . . . . . . . . . .  14
     1.10. Reserved Property Names . . . . . . . . . . . . . . . . .  14
   2.  Card  . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
     2.1.  Metadata properties . . . . . . . . . . . . . . . . . . .  14
       2.1.1.  @type . . . . . . . . . . . . . . . . . . . . . . . .  14
       2.1.2.  @version  . . . . . . . . . . . . . . . . . . . . . .  14
       2.1.3.  created . . . . . . . . . . . . . . . . . . . . . . .  15
       2.1.4.  kind  . . . . . . . . . . . . . . . . . . . . . . . .  15
       2.1.5.  locale  . . . . . . . . . . . . . . . . . . . . . . .  15
       2.1.6.  members . . . . . . . . . . . . . . . . . . . . . . .  16
       2.1.7.  prodId  . . . . . . . . . . . . . . . . . . . . . . .  16
       2.1.8.  relatedTo . . . . . . . . . . . . . . . . . . . . . .  16
       2.1.9.  uid . . . . . . . . . . . . . . . . . . . . . . . . .  17
       2.1.10. updated . . . . . . . . . . . . . . . . . . . . . . .  17

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     2.2.  Name and Organization properties  . . . . . . . . . . . .  18
       2.2.1.  fullName  . . . . . . . . . . . . . . . . . . . . . .  18
       2.2.2.  name  . . . . . . . . . . . . . . . . . . . . . . . .  18
       2.2.3.  nickNames . . . . . . . . . . . . . . . . . . . . . .  21
       2.2.4.  organizations . . . . . . . . . . . . . . . . . . . .  22
       2.2.5.  speakToAs . . . . . . . . . . . . . . . . . . . . . .  23
       2.2.6.  titles  . . . . . . . . . . . . . . . . . . . . . . .  24
     2.3.  Contact properties  . . . . . . . . . . . . . . . . . . .  25
       2.3.1.  emails  . . . . . . . . . . . . . . . . . . . . . . .  25
       2.3.2.  onlineServices  . . . . . . . . . . . . . . . . . . .  26
       2.3.3.  phones  . . . . . . . . . . . . . . . . . . . . . . .  27
       2.3.4.  preferredContactChannels  . . . . . . . . . . . . . .  29
       2.3.5.  preferredLanguages  . . . . . . . . . . . . . . . . .  30
     2.4.  Calendaring and Scheduling properties . . . . . . . . . .  31
       2.4.1.  calendars . . . . . . . . . . . . . . . . . . . . . .  31
       2.4.2.  schedulingAddresses . . . . . . . . . . . . . . . . .  32
     2.5.  Address and Location properties . . . . . . . . . . . . .  33
       2.5.1.  addresses . . . . . . . . . . . . . . . . . . . . . .  33
     2.6.  Resource properties . . . . . . . . . . . . . . . . . . .  36
       2.6.1.  cryptoKeys  . . . . . . . . . . . . . . . . . . . . .  36
       2.6.2.  directories . . . . . . . . . . . . . . . . . . . . .  36
       2.6.3.  links . . . . . . . . . . . . . . . . . . . . . . . .  37
       2.6.4.  media . . . . . . . . . . . . . . . . . . . . . . . .  38
     2.7.  Multilingual properties . . . . . . . . . . . . . . . . .  39
       2.7.1.  localizations . . . . . . . . . . . . . . . . . . . .  39
     2.8.  Additional properties . . . . . . . . . . . . . . . . . .  42
       2.8.1.  anniversaries . . . . . . . . . . . . . . . . . . . .  42
       2.8.2.  keywords  . . . . . . . . . . . . . . . . . . . . . .  44
       2.8.3.  notes . . . . . . . . . . . . . . . . . . . . . . . .  44
       2.8.4.  personalInfo  . . . . . . . . . . . . . . . . . . . .  45
   3.  Implementation Status . . . . . . . . . . . . . . . . . . . .  46
     3.1.  IIT-CNR/Registro.it . . . . . . . . . . . . . . . . . . .  47
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  47
     4.1.  Media Type Registration . . . . . . . . . . . . . . . . .  47
     4.2.  Creation of the "JSContact Properties" Registry . . . . .  49
       4.2.1.  Preliminary Community Review  . . . . . . . . . . . .  49
       4.2.2.  Submit Request to IANA  . . . . . . . . . . . . . . .  50
       4.2.3.  Designated Expert Review  . . . . . . . . . . . . . .  50
       4.2.4.  Change Procedures . . . . . . . . . . . . . . . . . .  50
       4.2.5.  "JSContact Properties" Registry Template  . . . . . .  51
       4.2.6.  Initial Contents for the "JSContact Properties"
               Registry  . . . . . . . . . . . . . . . . . . . . . .  52
     4.3.  Creation of the "JSContact Types" Registry  . . . . . . .  61
       4.3.1.  "JSContact Types" Registry Template . . . . . . . . .  61
       4.3.2.  Initial Contents for the "JSContact Types"
               Registry  . . . . . . . . . . . . . . . . . . . . . .  62
     4.4.  Creation of the "JSContact Enum Values" Registry  . . . .  64
       4.4.1.  "JSContact Enum Values" Registry Property Template  .  64

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       4.4.2.  "JSContact Enum Values" Registry Value Template . . .  64
       4.4.3.  Initial Contents for the "JSContact Enum Values"
               Registry  . . . . . . . . . . . . . . . . . . . . . .  65
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  73
     5.1.  JSON Parsing  . . . . . . . . . . . . . . . . . . . . . .  73
     5.2.  URI Values  . . . . . . . . . . . . . . . . . . . . . . .  74
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  74
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .  74
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  76
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  77

1.  Introduction

   This document defines a data model for contact card data normally
   used in address book or directory applications and services.  It aims
   to be an alternative to the vCard data format [RFC6350].

   The key design considerations for this data model are as follows:

   *  The data model and set of attributes should mostly be compatible
      with the one defined for the vCard data format [RFC6350] and
      extensions ([RFC6473], [RFC6474], [RFC6715], [RFC6869],
      [RFC8605]).  The specification should add new attributes or value
      types where appropriate.  Not all existing vCard definitions need
      an equivalent in JSContact, especially if the vCard definition is
      considered to be obsolete or otherwise inappropriate.  Conversion
      between the data formats need not fully preserve semantic meaning.

   *  The attributes of the card data represented must be described as a
      simple key-value pair, reducing complexity of its representation.

   *  The data model should avoid all ambiguities and make it difficult
      to make mistakes during implementation.

   *  Extensions, such as new properties and components, MUST NOT lead
      to requiring an update to this document.

   The representation of this data model is defined in the I-JSON format
   [RFC7493], which is a strict subset of the JavaScript Object Notation
   (JSON) Data Interchange Format [RFC8259].  Using JSON is mostly a
   pragmatic choice: its widespread use makes JSContact easier to adopt,
   and the availability of production-ready JSON implementations
   eliminates a whole category of parser-related interoperability
   issues.

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1.1.  Relation to the xCard and jCard formats

   The xCard [RFC6351] and jCard [RFC7095] specifications define
   alternative representations for vCard data, in XML and JSON format
   respectively.  Both explicitly aim to not change the underlying data
   model.  Accordingly, they are regarded as equal to vCard in the
   context of this document.

1.2.  Notational Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.3.  ABNF Notations

   The ABNF definitions in this document use the notations of [RFC5234].
   ABNF rules not defined in this document either are defined in
   [RFC5234] (such as the ABNF for CRLF, WSP, DQUOTE, VCHAR, ALPHA, and
   DIGIT) or [RFC6350].

1.4.  Type Signatures

   Type signatures are given for all JSON values in this document.  The
   following conventions are used:

   *  * - The type is undefined (the value could be any type, although
      permitted values may be constrained by the context of this value).

   *  String - The JSON string type.

   *  Number - The JSON number type.

   *  Boolean - The JSON boolean type.

   *  A[B] - A JSON object where the keys are all of type A, and the
      values are all of type B.

   *  A[] - A JSON array of values of type A.

   *  A|B - The value is either of type A or of type B.

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1.5.  Data types

   In addition to the standard JSON data types, a couple of additional
   data types are common to the definitions of JSContact objects and
   properties.

1.5.1.  Id

   Where Id is given as a data type, it means a String of at least 1 and
   a maximum of 255 octets in size, and it MUST only contain characters
   from the URL and Filename Safe base64url alphabet, as defined in
   Section 5 of [RFC4648], excluding the pad character (=).  This means
   the allowed characters are the ASCII alphanumeric characters (A-Za-
   z0-9), hyphen (-), and underscore (_).

   In many places in JSContact a JSON map is used where the map keys are
   of type Id and the map values are all the same type of object.  This
   construction represents an unordered set of objects, with the added
   advantage that each entry has a name (the corresponding map key).
   This allows for more concise patching of objects, and, when
   applicable, for the objects in question to be referenced from other
   objects within the JSContact object.  The map keys MUST be preserved
   across multiple versions of the JSContact object.

   Unless otherwise specified for a particular property, there are no
   uniqueness constraints on an Id value (other than, of course, the
   requirement that you cannot have two values with the same key within
   a single JSON map).  For example, two Card (Section 2) objects might
   use the same Ids in their respective photos properties.  Or within
   the same Card object the same Id could appear in the emails and
   phones properties.  These situations do not imply any semantic
   connections among the objects.

1.5.2.  Int and UnsignedInt

   Where Int is given as a data type, it means an integer in the range
   -2^53+1 <= value <= 2^^53-1, the safe range for integers stored in a
   floating-point double, represented as a JSON Number.

   Where UnsignedInt is given as a data type, it means an integer in the
   range 0 <= value <= 2^53-1, represented as a JSON Number.

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1.5.3.  PatchObject

   A PatchObject is of type String[*], and represents an unordered set
   of patches on a JSON object.  Each key is a path represented in a
   subset of JSON pointer format [RFC6901].  The paths have an implicit
   leading /, so each key is prefixed with / before applying the JSON
   pointer evaluation algorithm.

   A patch within a PatchObject is only valid if all the following
   conditions apply:

   1.  The pointer MUST NOT reference inside an array (i.e., you MUST
       NOT insert/delete from an array; the array MUST be replaced in
       its entirety instead).

   2.  All parts prior to the last (i.e., the value after the final
       slash) MUST already exist on the object being patched.

   3.  There MUST NOT be two patches in the PatchObject where the
       pointer of one is the prefix of the pointer of the other, e.g.,
       addresses/1/city and addresses.

   4.  The value for the patch MUST be valid for the property being set
       (of the correct type and obeying any other applicable
       restrictions), or if null the property MUST be optional.

   The value associated with each pointer determines how to apply that
   patch:

   *  If null, remove the property from the patched object.  If the key
      is not present in the parent, this a no-op.

   *  If non-null, set the value given as the value for this property
      (this may be a replacement or addition to the object being
      patched).

   A PatchObject does not define its own @type property.  Instead, a
   @type property in a patch MUST be handled as any other patched
   property value.

   Implementations MUST reject in its entirety a PatchObject if any of
   its patches are invalid.  Implementations MUST NOT apply partial
   patches.

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1.5.4.  Resource

   This data type defines a resource associated with the entity
   represented by this card, identified by a URI [RFC3986].  Several
   property definitions later in this document refer to the Resource
   data type as the basis for their property-specific value types.  The
   Resource data type defines the properties that are common to all of
   them.  Property definitions making use of Resource MAY define
   additional properties for their value types.

   A Resource object has the following properties:

   *  @type: String (mandatory).  The allowed values are defined in the
      property definition that makes use of the Resource type.

   *  type: String (optional).  The type of the resource.  The allowed
      values are defined in the property definition that makes use of
      the Resource type.

   *  uri: String (mandatory).  The resource value.  This MUST be a
      _URI_ as defined in Section 3 of [RFC3986] and updates.

   *  mediaType: String (optional).  Used for URI resource values.
      Provides the media type [RFC2046] of the resource identified by
      the URI.

   *  contexts: String[Boolean] (optional).  The contexts in which to
      use this resource.  Also see Section 1.6.1.

   *  pref: UnsignedInt (optional).  The preference of this resource in
      relation to other resources.  Also see Section 1.6.3.

   *  label: String (optional).  A custom label for the value, see
      Section 1.6.2.

1.5.5.  UTCDateTime

   This is a string in [RFC3339] date-time format, with the further
   restrictions that any letters MUST be in uppercase, and the time
   offset MUST be the character Z.  Fractional second values MUST NOT be
   included unless non-zero and MUST NOT have trailing zeros, to ensure
   there is only a single representation for each date-time.

   For example, 2010-10-10T10:10:10.003Z is conformant, but
   2010-10-10T10:10:10.000Z is invalid and is correctly encoded as
   2010-10-10T10:10:10Z.

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1.6.  Common properties

   Most of the properties in this document are specific to a single
   JSContact object type.  Such properties are defined along with the
   respective object type.  The properties in this section are common to
   multiple data types and are defined here to avoid repetition.  Note
   that these properties MUST only be set for a JSContact object if they
   are explicitly mentioned to be allowed for this object type.

1.6.1.  The contexts property

   Type: String[Boolean]

   This property associates contact information with one or more
   contexts in which it should be used.  For example, someone might have
   distinct phone numbers for work and private contexts, and may set the
   desired context on the respective phone number in the phones
   (Section 2.3.3) property.

   This document defines the following common contexts.  Additional
   contexts may be defined in the properties or data types that make use
   of this property, may be registered in a future RFC, or be vendor-
   specific (Section 1.9.1).

   *  private: The contact information may be used to contact in a
      private context.

   *  work: The contact information may be used to contact in a
      professional context.

1.6.2.  The label property

   Type: String

   This property allows to associate contact data with user-defined
   labels.  Such labels may be set for phone numbers, email addresses
   and resources.  Typically, these labels are displayed along with
   their associated contact data in graphical user interfaces.  While
   this specification does not place further restrictions on the value,
   implementors SHOULD take in mind that labels best be succinct, so
   that they properly display on small graphical interfaces and screens.

1.6.3.  The pref property

   Type: UnsignedInt

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   This property allows to define a preference order for contact
   information.  For example, a card holder may have two email addresses
   and prefer to be contacted with one of them.

   Its value MUST be in the range 1 and 100.  Lower values correspond to
   a higher level of preference, with 1 being most preferred.  If no
   preference is set, then the contact information MUST be interpreted
   as being least preferred.

   Note that the preference only is defined in relation to contact
   information of the same type.  For example, the preference orders
   within emails and phone numbers are independent of each other.

1.7.  Versioning

   Every instance of a JSContact Card (Section 2) indicates which
   JSContact version its IANA-registered properties and values are based
   on.  The version is indicated both in the @version (Section 2.1.2)
   property within the Card and in the version (Section 4.1) parameter
   of the JSContact MIME content type.  All IANA-registered elements
   indicate the version at which they got introduced or obsoleted.

   Implementors are RECOMMENDED to always support the latest version.

1.7.1.  Version Scheme

   A JSContact version consists of a numeric major and minor version.
   Later versions are numerically higher than former versions, with the
   major version being more significant than the minor version.  A
   version value is produced by the ABNF

   jsversion = 1*DIGIT "." 1*DIGIT

   Differing major version values indicate substantial differences in
   JSContact semantics and format.  Implementations MUST be prepared
   that property definitions and other JSContact elements differ in a
   backwards-incompatible manner.

   Differing minor version values indicate additions that enrich
   JSContact data, but do not introduce backwards-incompatible changes.
   Typically, these are new property enum values or properties with
   narrow semantic scope.  A new minor version MUST NOT require
   implementations to change their processing of JSContact data.

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1.7.2.  Version Updates

   If Expert Review or the IETF working group decides that a new major
   JSContact version is required, a new standard RFC document MUST be
   published.  Such an RFC document MUST specify all changes to the
   former JSContact version.  An RFC document is not required to change
   the minor JSContact version.

   Every new JSContact version MUST be registered at IANA in the
   JSContact Enum Value registry Table 6.

1.8.  Validating JSContact Properties

   JSContact objects are represented as I-JSON objects [RFC7493] and the
   keys of such objects are called properties.  This specification
   distinguishes between three kinds of properties with regards to
   validation: IANA-registered properties and unknown properties are
   defined in this section, while vendor-specific properties are defined
   in Section 1.9.1.  A JSContact object is invalid if any its
   properties are invalid.  If a JSContact object is valid,
   implementations MUST preserve all its properties.

1.8.1.  IANA-registered Properties

   An IANA-registered property is any property that has been registered
   according to the IANA property registry rules as outlined in
   Section 4.  All properties defined in this specification are IANA-
   registered properties.

   Implementations MUST validate IANA-registered properties in JSContact
   data, unless they are unknown to the implementation (see
   Section 1.8.2).  They MUST reject invalid IANA-registered properties.
   A property is invalid if its name matches the name of an IANA-
   registered property but the value violates its definition according
   to the JSContact specification version defined in the Card object
   @version property (Section 2.1.2).

   IANA-registered property names MUST NOT contain US-ASCII control
   characters (U+0000 to U+001F, U+007F), the COLON (U+003A) or
   QUOTATION MARK (U+0022) characters.  They SHOULD only contain US-
   ASCII alphanumeric characters (the ALPHA and DIGIT rules defined in
   Section 6.1 of [RFC2234]), but notable exceptions of this rule are
   metadata properties such as @type and @version defined in later
   sections of this document.  IANA-registered property names SHOULD be
   notated in lower camel case.

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1.8.2.  Unknown Properties

   Implementations may encounter JSContact data where a property name is
   unknown to that implementation, but the name adheres to the
   restrictions of an IANA-registered property.

   Implementations MUST NOT treat such properties as invalid.  Instead,
   they MUST preserve them in the JSContact object.  Implementations
   that create or update JSContact data MUST only set IANA-registered
   properties or vendor-specific properties, but MUST preserve any
   already existing unknown properties.  This is to allow applications
   and services to interoperate without data loss, even if they do not
   implement the same set of JSContact extensions.

1.9.  Vendor-Specific Extensions

   Vendors may extend properties and values for experimentation or to
   store contacts data that only is useful for a single service or
   application.  Such extensions are not meant for interoperation and
   vendors MUST NOT expect other implementations to process their
   contents.  If instead interoperation is desired, vendors are strongly
   encouraged to define and register new properties, types and values at
   IANA.  Typically, sending a short description to the IETF working
   group mailing list is enough for Expert Review to make a decision.
   Notably, publishing a new RFC document is not required in the general
   case.  Section 4 defines how to register new properties, types or
   values at IANA.  Section 1.8.1 defines the naming conventions for
   IANA-registered elements.

1.9.1.  Vendor-specific Properties

   Vendor-specific properties MAY be set in any JSContact object.
   Implementations MUST preserve vendor-specific properties in JSContact
   data, irrespective if they know their use.  They MUST NOT reject the
   property value as invalid, unless they are in control of the vendor-
   specific property.

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   Vendor-specific property names MUST start with a vendor-specific
   prefix, followed by the COLON character (U+003A), followed by a name
   consisting of any other non-control ASCII or non-ASCII characters.
   The vendor-specific prefix SHOULD be a domain name under control of
   the service or application that sets the property, but it need not
   resolve in the Domain Name System [RFC1034] and [RFC1035].  The
   prefix ietf.org and its sub-domain names are reserved for IETF
   specifications.  The name following the prefix MUST NOT contain the
   QUOTATION MARK (U+0022) character.  It SHOULD NOT contain the TILDE
   (U+007E) and SOLIDUS (U+002F) characters, as these require special-
   escaping when encoding a JSON Pointer [RFC6901] including that
   property.

   The ABNF rule v-extension formally defines valid vendor-specific
   property names.  Note that the vendor prefix allows for more values
   than are allowed as Internationalized Domain Names (IDN) [RFC8499].
   This is to allow JSContact implementations simply validate property
   names without implementing the full set of rules that apply to domain
   names.

   v-extension = v-prefix ":" v-name

   v-prefix = v-label *("." v-label)

   v-label = alnum-int / alnum-int *(alnum-int / "-") alnum-int

   alnum-int = ALPHA / DIGIT / NON-ASCII
     ; see RFC 6350 Section 3.3

   v-name = 1*(WSP / "!" / %x23-7e / NON-ASCII)
     ; any characters except CTLs and DQUOTE
     ; use of "/" (%x2f) and "~" (%x7e) is discouraged

   The value of vendor-specific properties can be any valid JSON value,
   and naming restrictions do not apply to such values.  Specifically,
   if the property value is a JSON object then the keys of such objects
   need not be named as vendor-specific properties.

   The following all are valid examples of vendor-specific properties.

   "example.com:foo": "bar",
   "example.com:foo2": {
     "bar": "baz"
   }

                                  Figure 1

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1.9.2.  Vendor-specific Values

   Some JSContact IANA-registered properties allow their values to be
   vendor-specific.  One such example is the kind property
   Section 2.1.4, which enumerates its standard values but also allows
   for arbitrary vendor-specific values.  Such vendor-specific values
   MUST be valid v-extension values as defined in Section 1.9.1.  This
   is an example for a vendor-specific value:

   "kind": "example.com:kind:foo"

                                  Figure 2

   Vendors are strongly encouraged to specify new standard values once a
   vendor-specific turns out to be useful also for other systems.

1.10.  Reserved Property Names

   This specification reserves the property name extra at IANA.  A
   JSContact object MUST NOT be defined to have a property with this
   name.  This is to provide implementations with a name to map unknown
   or vendor-specific properties to, and which never may occur as a
   property in a JSContact object.

2.  Card

   MIME type: application/jscontact+json;type=card

   A Card object stores information about a person, organization or
   company.

2.1.  Metadata properties

2.1.1.  @type

   Type: String (mandatory).

   Specifies the type of this object.  This MUST be Card.

2.1.2.  @version

   Type: String (mandatory).

   Specifies the JSContact version used to define this card.  The value
   MUST be one of the IANA-registered JSContact Enum Values for the
   @version property.  This specification registers the JSContact
   version value 1.0 (Table 6).

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   "@version": "1.0",

                         Figure 3: @version example

2.1.3.  created

   Type: UTCDateTime (optional).

   The date and time when this Card object was created.

   "created": "1994-09-30T14:35:10Z",

                         Figure 4: created example

2.1.4.  kind

   Type: String (optional).  The kind of the entity the Card represents.

   The value MUST be either one of the following values, registered in a
   future RFC, or a vendor-specific value (Section 1.9.1):

   *  individual: a single person

   *  group: a group person of persons or entities

   *  org: an organization

   *  location: a named location

   *  device: a device, such as appliances, computers, or network
      elements

   *  application: a software application

   "kind": "individual",

                           Figure 5: kind example

2.1.5.  locale

   Type: String (optional).

   This is the language tag, as defined in [RFC5646], that best
   describes the locale used for text in the card.  Note that such
   values MAY be localized in the localizations property Section 2.7.1.

   "locale": "de-AT",

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                          Figure 6: locale example

2.1.6.  members

   Type: String[Boolean] (optional).

   This identifies the set of cards that are members of this group card.
   Each key in the set is the uid property value of the member, each
   boolean value MUST be true.  If this property is set, then the value
   of the kind property MUST be group.

   The opposite is not true.  A group Card will usually contain the
   members property to specify the members of the group, but it is not
   required to.  A group Card without the members property can be
   considered an abstract grouping, or one whose members are known
   empirically (e.g.  "IETF Participants").

   "kind": "group",
   "fullName": "The Doe family",
   "uid": "urn:uuid:ab4310aa-fa43-11e9-8f0b-362b9e155667",
   "members": {
     "urn:uuid:03a0e51f-d1aa-4385-8a53-e29025acd8af": true,
     "urn:uuid:b8767877-b4a1-4c70-9acc-505d3819e519": true
   }

                         Figure 7: members example

2.1.7.  prodId

   Type: String (optional).

   The identifier for the product that created the Card object.

   "prodId": "-//ONLINE DIRECTORY//NONSGML Version 1//EN"

                          Figure 8: prodId example

2.1.8.  relatedTo

   Type: String[Relation] (optional).

   Relates the object to other Card objects.  This is represented as a
   map, where each key is the uid of the related Card and the value
   defines the relation.  The Relation object has the following
   properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Relation.

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   *  relation: String[Boolean] (optional, default: empty Object)
      Describes how the linked object is related to the linking object.
      The relation is defined as a set of relation types.  If empty, the
      relationship between the two objects is unspecified.  Keys in the
      set MUST be one of the RELATED property [RFC6350] type parameter
      values, or an IANA-registered value, or a vendor-specific value
      (Section 1.9.1).  The value for each key in the set MUST be true.

   "relatedTo": {
     "urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6": {
       "@type": "Relation",
       "relation": {
         "friend": true
       }
     },
     "8cacdfb7d1ffdb59@example.com": {
       "@type": "Relation",
       "relation": {}
     }
   }

                        Figure 9: relatedTo example

2.1.9.  uid

   Type: String (mandatory).

   An identifier, used to associate the object as the same across
   different systems, address books and views.  The value SHOULD be a
   URN [RFC8141] but for compatibility with [RFC6350] it MAY also be a
   URI [RFC3986] or free-text value.  The value of the URN SHOULD be in
   the uuid namespace [RFC4122].  As of this writing, a revision of
   [RFC4122] is being worked on and is likely to introduce new UUID
   versions and best practices to generate global unique identifiers.
   Implementors SHOULD follow any recommendations described there.
   Until then, implementations SHOULD generate identifiers using the
   random or pseudo-random UUID version described in Section 4.4 of
   [RFC4122].

   "uid": "urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6"

                           Figure 10: uid example

2.1.10.  updated

   Type: UTCDateTime (optional).

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   The date and time when the data in this Card object was last
   modified.

   "updated": "1995-10-31T22:27:10Z"

                         Figure 11: updated example

2.2.  Name and Organization properties

2.2.1.  fullName

   Type: String (optional).

   This is the full name of the entity represented by this card.  The
   purpose of this property is to define a name even if the individual
   name components are not known.  If the name property is set, the
   fullName property SHOULD NOT be set.  If both properties are set,
   applications SHOULD display the contents of the name property as the
   name of the entity represented by this card.  Applications SHOULD NOT
   store the concatenated name component values of the name property in
   the fullName property value.

   "fullName": "Mr.  John Q.  Public, Esq."

                        Figure 12: fullName example

2.2.2.  name

   Type: Name (optional).

   The name of the entity represented by this Card.

   A Name object has the following properties

   *  @type: Name (mandatory).  Specifies the type of this object.  This
      MUST be Name.

   *  components: NameComponent[] (mandatory).  The components making up
      the name.  The component list MUST have at least one entry.

      Name components SHOULD be ordered such that their values joined as
      a String produce a valid full name of this entity.  This
      specification does not mandate how to do this but recommends the
      following: If at least one of two adjacent name components is of
      type separator then implementations SHOULD join their values
      without any additional character.  Otherwise, inserting a single
      Space character in between name component values is a good choice.

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   *  sortAs: String[String] (optional).

      This defines how this name lexicographically sorts in relation to
      other names when compared by a name component type.  The key in
      the map defines the name component type.  The value for that key
      defines the verbatim string to compare when sorting by this name
      component type.  Absence of a key indicates that this name
      component type should not be considered during sort.  Sorting by
      that missing name component type or if the sortAs property is not
      set is implementation-specific.

      Each key in the map MUST be a valid name component type value as
      defined for the type property of the NameComponent object (see
      below).  For each key in the map there MUST exist at least one
      NameComponent object having that type in the components property
      of this name.

      Figure 13 illustrates the use of sortAs.  The property value
      indicates that the middle name followed by both surnames should be
      used when sorting this name by surname.  The absence of the middle
      indicates that the middle name on its own should be disregarded
      during sort.  Even though the name only contains one name
      component for the given name, the sortAs property still explicitly
      defines how to sort by given name as otherwise sorting by it would
      be undefined.

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      "name": {
        "@type": "Name",
        "components": [
          {
            "@type": "NameComponent",
            "type": "given",
            "value": "Robert"
          },
          {
            "@type": "NameComponent",
            "type": "middle",
            "value": "Pau"
          },
          {
            "@type": "NameComponent",
            "type": "surname",
            "value": "Shou"
          },
          {
            "@type": "NameComponent",
            "type": "surname",
            "value": "Chang"
          }
        ],
        "sortAs": {
          "surname": "Pau Shou Chang",
          "given": "Robert"
        }
      }

                           Figure 13: name example

   A NameComponent object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be NameComponent.

   *  value: String (mandatory).  The value of this name component.

   *  type: String (mandatory).  The type of this name component.  The
      value MUST be either one of the following values, registered in a
      future RFC, or a vendor-specific value (Section 1.9.1):

      -  prefix.  The value is an honorific title(s), e.g.  "Mr", "Ms",
         "Dr".

      -  given.  The value is a given name, also known as "first name",
         "personal name".

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      -  surname.  The value is a surname, also known as "last name",
         "family name".

      -  middle.  The value is a middle name, also known as "additional
         name".

      -  suffix.  The value is an honorific suffix, e.g.  "B.A.",
         "Esq.".

      -  separator.  A formatting separator for two name components.
         The value property of the component includes the verbatim
         separator, for example a hyphen character.

   *  rank: UnsignedInt (optional, default: 1).  Defines the rank of
      this name component to other name components of the same type.  If
      set, the property value MUST be higher than or equal to 1.

      For example, two name components of type surname may have their
      rank property value set to 1 and 2, respectively.  In this case,
      the first name component defines the surname, and the second name
      component the secondary surname.

      Note that this property value does not indicate the order in which
      to print name components of the same type.  Some cultures print
      the secondary surname before the first surname, others the first
      before the second.  Implementations SHOULD inspect the locale
      property of the Card object to determine the appropriate
      formatting.  They MAY print name components in order of appearance
      in the components property of the Name object.

2.2.3.  nickNames

   Type: Id[NickName] (optional).

   The nick names of the entity represented by this card.  A NickName
   object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be NickName.

   *  name: String (mandatory).  The nick name.

   *  contexts: String[Boolean] (optional) The contexts in which to use
      this nick name.  Also see Section 1.6.1.

   *  pref: UnsignedInt (optional).  The preference of this nick name in
      relation to other nick names.  Also see Section 1.6.3.

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   "nickNames": {
     "k391": {
       "@type": "NickName",
       "name": "Johnny"
     }
   }

                        Figure 14: nickNames example

2.2.4.  organizations

   Type: Id[Organization] (optional).

   The companies or organization names and units associated with this
   card.  An Organization object has the following properties, of which
   at least one of name and units MUST be set:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Organization.

   *  name: String (optional).  The name of this organization.

   *  units: OrgUnit[] (optional).  A list of organizational units.  If
      set, the list MUST contain at least one entry.

   *  sortAs: String (optional).  This defines how this organization
      name lexicographically sorts in relation to other organizations
      when compared by name.  The value defines the verbatim string
      value to compare.  In absence of this property, the name property
      value SHOULD be used for comparison.

   *  contexts: String[Boolean] (optional).  The contexts in which
      association with this organization apply.  For example, membership
      in a choir may only apply in a private context.  Also see
      Section 1.6.1.

   A OrgUnit object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be OrgUnit.

   *  name: String (optional).  The name of this organizational unit.
      If set, the value MUST be a non-empty string.

   *  sortAs: String (optional).  This defines how this organization
      unit name lexicographically sorts in relation to other
      organizational units of the same level when compared by name.  The
      level is defined by the array index of this organizational unit in

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      the units property of the Organization object.  The property value
      defines the verbatim string value to compare.  In absence of this
      property, the name property value SHOULD be used for comparison.

   "organizations": {
     "o1": {
       "@type": "Organization",
       "name": "ABC, Inc.",
       "units": [
         {
           "@type": "OrgUnit",
           "name": "North American Division"
         },
         {
           "@type": "OrgUnit",
           "name": "Marketing"
         }
       ],
       "sortAs": "ABC"
     }
   }

                      Figure 15: organizations example

2.2.5.  speakToAs

   Type: SpeakToAs (optional).

   Provides information how to address, speak to or refer to the entity
   that is represented by this card.  A SpeakToAs object has the
   following properties, of which at least one property other than @type
   MUST be set:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be SpeakToAs.

   *  grammaticalGender: String (optional).  Defines which grammatical
      gender to use in salutations and other grammatical constructs.
      Allowed values are:

      -  animate

      -  female

      -  inanimate

      -  male

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      -  neuter

      Note that the grammatical gender does not allow to infer the
      gender identities or assigned sex of the contact.

   *  pronouns: Id[Pronouns] (optional).  Defines the pronouns that the
      contact chooses to use for themselves.

   A Pronouns object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Pronouns.

   *  pronouns: String (mandatory).  Defines the pronouns.  Any value or
      form is allowed.  Examples in English include she/her and
      they/them/theirs.  The value MAY be overridden in the
      localizations property (Section 2.7.1).

   *  contexts: String[Boolean] (optional).  The contexts in which to
      use these pronouns.  Also see Section 1.6.1.

   *  pref: UnsignedInt (optional).  The preference of these pronouns in
      relation to other pronouns in the same context.  Also see
      Section 1.6.3.

   "speakToAs": {
     "grammaticalGender": "neuter",
     "pronouns": {
       "k19": {
         "@type": "Pronouns",
         "pronouns": "they/them",
         "pref": 2
       },
       "k32": {
         "@type": "Pronouns",
         "pronouns": "xe/xir",
         "pref": 1
       }
     }
   }

                        Figure 16: speakToAs example

2.2.6.  titles

   Type : Id[Title] (optional).

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   The job titles or functional positions of the entity represented by
   this card.  A Title has object the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Title.

   *  name: String (mandatory).  The title or role name of the entity
      represented by this card.

   *  type: String (optional, default title).  Describes the
      organizational or situational type of this title.  Some
      organizations and individuals distinguish between _titles_ as
      organizational positions and _roles_ as more temporary
      assignments, such as in project management.  If set, the property
      value MUST either be one of title and role, or be registered in a
      future RFC, or a vendor-specific value (Section 1.9.1).

   *  organization: Id (optional).  The id of the organization in which
      this title is held.

   "titles": {
     "le9": {
       "@type": "Title",
       "type": "title",
       "name": "Research Scientist"
     },
     "k2": {
       "@type": "Title",
       "type": "role",
       "name": "Project Leader",
       "organization": "o2"
     }
   },
   "organizations": {
     "o2": {
       "@type": "Organization",
       "name": "ABC, Inc."
     }
   }

                         Figure 17: titles example

2.3.  Contact properties

2.3.1.  emails

   Type: Id[EmailAddress] (optional).

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   The email addresses to contact the entity represented by this card.
   An EmailAddress object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be EmailAddress.

   *  address: String (mandatory).  The email address.  This MUST be an
      _addr-spec_ value as defined in Section 3.4.1 of [RFC5322].

   *  contexts: String[Boolean] (optional).  The contexts in which to
      use this email address.  Also see Section 1.6.1.

   *  pref: UnsignedInt (optional).  The preference of this email
      address in relation to other email addresses.  Also see
      Section 1.6.3.

   *  label: String (optional).  A custom label for the value, see
      Section 1.6.2.

   "emails": {
     "e1": {
       "@type": "EmailAddress",
       "contexts": {
         "work": true
       },
       "address": "jqpublic@xyz.example.com"
     },
     "e2": {
       "@type": "EmailAddress",
       "address": "jane_doe@example.com",
       "pref": 1
     }
   }

                         Figure 18: emails example

2.3.2.  onlineServices

   Type: Id[OnlineService] (optional).

   The online services that are associated with the entity represented
   by this card.  This can be messaging services, social media profiles,
   and other.  An OnlineService object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be OnlineService.

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   *  service: String (optional).  The name of the online service or
      protocol.  This SHOULD be the canonical service name including
      capitalization.  Examples are GitHub, kakao, Mastodon.

   *  user: String (mandatory).  This identifies the entity represented
      by this card at this online service.  The type property defines
      the how to interpret the value.

   *  type: String (mandatory).  This defines the type of the identifier
      in the user property.  The type MUST be either one of the
      following values, registered in a future RFC, or a vendor-specific
      value (Section 1.9.1):

      -  impp: The value of the user property is a URI primarily used
         for instant messaging.  The service property SHOULD be set.

      -  uri: The value of the user property is a service-specific URI,
         such as for a social media service.  The service property
         SHOULD be set.

      -  username: The value of the user property is a service-specific
         username, such as for a social media service.  Any free-text
         value is allowed.  The service property MUST be set.

   *  contexts: String[Boolean] (optional).  The contexts in which to
      use this service.  Also see Section 1.6.1.

   *  pref: UnsignedInt (optional).  The preference of this service in
      relation to other services.  Also see Section 1.6.3.

   *  label: String (optional).  A custom label for the value, see
      Section 1.6.2.

   "onlineServices": {
     "x1": {
       "@type": "OnlineService",
       "user": "xmpp:alice@example.com",
       "type": "impp",
       "pref": 1
     }
   }

                     Figure 19: onlineServices example

2.3.3.  phones

   Type: Id[Phone] (optional).

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   The phone numbers to contact the entity represented by this card.  A
   Phone object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Phone.

   *  number: String (mandatory).  The phone number, as either a URI or
      free-text.  Typical URI schemes are the [RFC3966] tel or [RFC3261]
      sip schemes, but any URI scheme is allowed.

   *  features: String[Boolean] (optional).  The set of contact features
      that this phone number may be used for.  The set is represented as
      an object, with each key being a method type.  The boolean value
      MUST be true.  The method type MUST be either one of the following
      values, registered in a future RFC, or a vendor-specific value
      (Section 1.9.1):

      -  voice The number is for calling by voice.

      -  fax The number is for sending faxes.

      -  pager The number is for a pager or beeper.

      -  text The number supports text messages (SMS).

      -  cell The number is for a cell phone.

      -  textphone The number is for a device for people with hearing or
         speech difficulties.

      -  video The number supports video conferencing.

   *  contexts: String[Boolean] (optional).  The contexts in which to
      use this number.  Also see Section 1.6.1.

   *  pref: UnsignedInt (optional).  The preference of this number in
      relation to other numbers.  Also see Section 1.6.3.

   *  label: String (optional).  A custom label for the value, see
      Section 1.6.2.

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   "phones": {
     "tel0": {
       "@type": "Phone",
       "contexts": {
         "private": true
       },
       "features": {
         "voice": true
       },
       "number": "tel:+1-555-555-5555;ext=5555",
       "pref": 1
     },
     "tel3": {
       "@type": "Phone",
       "contexts": {
         "work": true
       },
       "number": "tel:+33-01-23-45-67"
     }
   }

                         Figure 20: phones example

2.3.4.  preferredContactChannels

   Type : String[ContactChannelPreference[]] (optional).

   Defines which channel the entity represented by this card prefers to
   be contacted with.  The keys in the object MUST be either one of the
   following values, registered in a future RFC, or a vendor-specific
   value (Section 1.9.1):

   *  addresses.  The entity prefers to be contacted by postal delivery
      to one of the entries in addresses (Section 2.5.1).

   *  emails.  The entity prefers to be contacted by one of the entries
      in emails (Section 2.3.1).

   *  onlineServices.  The entity prefers to be contacted by one of the
      entries in onlineServices (Section 2.3.2).

   *  phones.  The entity prefers to be contacted by one of the entries
      in phones (Section 2.3.3).

   The values in the object are a (possibly empty) list of preferences
   for this contact channel.  A valid ContactChannelPreference object
   MUST have at least one of its properties set in addition to the @type
   property.

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   A ContactChannelPreference object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be ContactChannelPreference.

   *  contexts: String[Boolean] (optional).  Defines the contexts in
      which to use this contact channel.  Also see Section 1.6.1.

   *  pref: UnsignedInt (optional).  Defines the preference of this
      contact channel in relation to other contact channels with the
      same contexts.  Also see Section 1.6.3.

   "preferredContactChannels": {
     "emails": [
       {
         "@type": "ContactChannelPreference",
         "pref": 1
       }
     ],
     "phones": [
       {
         "@type": "ContactChannelPreference",
         "pref": 2
       }
     ]
   }

                Figure 21: preferredContactChannels example

2.3.5.  preferredLanguages

   Type : String[LanguagePreference[]] (optional).

   Defines the preferred languages for contacting the entity associated
   with this card.  The keys in the object MUST be [RFC5646] language
   tags.  The values are a (possibly empty) list of contact language
   preferences for this language.  A valid LanguagePreference object
   MUST have at least one of its properties set in addition to the @type
   property.

   A LanguagePreference object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be LanguagePreference.

   *  contexts: String[Boolean] (optional).  Defines the contexts in
      which to use this language.  Also see Section 1.6.1.

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   *  pref: UnsignedInt (optional).  Defines the preference of this
      language in relation to other languages of the same contexts.
      Also see Section 1.6.3.

   "preferredLanguages": {
     "en": [
       {
         "@type": "LanguagePreference",
         "contexts": {
           "work": true
         },
         "pref": 1
       }
     ],
     "fr": [
       {
         "@type": "LanguagePreference",
         "contexts": {
           "work": true
         },
         "pref": 2
       },
       {
         "@type": "LanguagePreference",
         "contexts": {
           "private": true
         }
       }
     ]
   }

                   Figure 22: preferredLanguages example

2.4.  Calendaring and Scheduling properties

2.4.1.  calendars

   Type: Id[CalendarResource] (optional).

   These are resources for calendaring, such as calendars to lookup
   free-busy information for the entity represented by this card.  A
   CalendarResource object has all properties of the Resource
   (Section 1.5.4) data type, with the following additional definitions:

   *  The @type property value MUST be CalendarResource.

   The type property value MUST be one of the following, or be defined
   in a future RFC or vendor-specific:

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   *  calendar The resource is a calendar that contains entries such as
      calendar events or tasks.

   *  freeBusy The resource allows for free-busy lookups, for example to
      schedule group events.

   "calendars": {
     "calA": {
       "@type": "CalendarResource",
       "type": "calendar",
       "uri": "ftp://ftp.example.com/calA.ics",
       "mediaType": "text/calendar"
     },
     "project-a": {
       "@type": "CalendarResource",
       "type": "freeBusy",
       "uri": "ftp://example.com/busy/project-a.ifb",
       "mediaType": "text/calendar"
     }
   }

                        Figure 23: calendars example

2.4.2.  schedulingAddresses

   Type: Id[SchedulingAddress] (optional).

   The scheduling addresses by which the entity may receive calendar
   scheduling invitations.  A SchedulingAddress object has the following
   properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be SchedulingAddress.

   *  uri: String (mandatory).  The address to use for calendar
      scheduling with this contact.  This MUST be a URI as defined in
      Section 3 of [RFC3986] and updates.

   *  contexts: String[Boolean] (optional).  The contexts in which to
      use this scheduling address.  Also see Section 1.6.1.

   *  pref: UnsignedInt (optional).  The preference of this scheduling
      address in relation to other scheduling address.  Also see
      Section 1.6.3.

   *  label: String (optional).  A custom label for the scheduling
      address, see Section 1.6.2.

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   "schedulingAddresses": {
     "sched1": {
       "@type": "SchedulingAddress",
       "uri": "mailto:janedoe@example.com"
     }
   }

                   Figure 24: schedulingAddresses example

2.5.  Address and Location properties

2.5.1.  addresses

   Type: Id[Address] (optional).

   A map of address ids to Address objects, containing physical
   locations.  An Address object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Address.

   *  street: StreetComponent[] (optional).  The street address.  The
      concatenation of the component values, separated by whitespace,
      SHOULD result in a valid street address for the address locale.
      Doing so, implementations MAY ignore any separator components.
      The StreetComponent object type is defined in the paragraph below.

   *  locality: String (optional).  The city, town, village, post town,
      or other locality within which the street address may be found.

   *  region: String (optional).  The province, such as a state, county,
      or canton within which the locality may be found.

   *  country: String (optional).  The country name.

   *  postcode: String (optional).  The postal code, post code, ZIP code
      or other short code associated with the address by the relevant
      country's postal system.

   *  countryCode: String (optional).  The ISO-3166-1 country code.

   *  coordinates: String (optional).  A [RFC5870] "geo:" URI for the
      address.

   *  timeZone: String (optional).  Identifies the time zone this
      address is located in.  This MUST be a time zone name registered
      in the IANA Time Zone Database (https://www.iana.org/time-zones)

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   *  contexts: String[Boolean] (optional).  The contexts of the address
      information.  The boolean value MUST be true.  In addition to the
      common contexts (Section 1.6.1), allowed key values are:

      -  billing An address to be used for billing.

      -  delivery An address to be used for delivering physical items.

   *  fullAddress: String (optional).  This is the full address,
      including street, region or country.  The purpose of this property
      is to define an address, even if the individual address components
      are not known.  If the street property is set, the fullAddress
      property SHOULD NOT be set.  If both properties are set,
      applications SHOULD display the contents of the street property as
      the street address of the entity represented by this card.
      Applications SHOULD NOT store the concatenated street component
      values of the street property in the fullAddress property value.

   *  pref: UnsignedInt (optional).  The preference of this address in
      relation to other addresses.  Also see Section 1.6.3.

   A StreetComponent object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be StreetComponent.

   *  type: String (mandatory).  The type of this street component.  The
      value MUST be either one of the following values, registered in a
      future RFC, or a vendor-specific value (Section 1.9.1):

      -  name.  The street name.

      -  number.  The street number.

      -  apartment.  The apartment number or identifier.

      -  room.  The room number or identifier.

      -  extension.  The extension designation or box number.

      -  direction.  The cardinal direction, e.g.  "North".

      -  building.  The building or building part this address is
         located in.

      -  floor.  The floor this address is located on.

      -  postOfficeBox.  The post office box number or identifier.

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      -  separator.  A separator for two street components.  The value
         property of the component includes the verbatim separator, for
         example a newline character.

      -  unknown.  A street component value for which no type is known.

   *  value: String (mandatory).  The value of this street component.

   "addresses": {
     "k23": {
       "@type": "Address",
       "contexts": {
         "work": true
       },
       "fullAddress": "54321 Oak St\nReston\nVA\n20190\nUSA",
       "street": [
         {
           "@type": "StreetComponent",
           "type": "name",
           "value": "Oak St"
         },
         {
           "@type": "StreetComponent",
           "type": "number",
           "value": "54321"
         }
       ],
       "locality": "Reston",
       "region": "VA",
       "country": "USA",
       "postcode": "20190",
       "countryCode": "US"
     },
     "k24": {
       "@type": "Address",
       "contexts": {
         "private": true
       },
       "fullAddress": "12345 Elm St\nReston\nVA\n20190\nUSA",
       "street": [
         {
           "@type": "StreetComponent",
           "type": "name",
           "value": "Elm St"
         },
         {
           "@type": "StreetComponent",
           "type": "number",

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           "value": "12345"
         }
       ],
       "locality": "Reston",
       "region": "VA",
       "country": "USA",
       "postcode": "20190",
       "countryCode": "US"
     }
   }

                        Figure 25: addresses example

2.6.  Resource properties

2.6.1.  cryptoKeys

   Type: Id[CryptoResource] (optional).

   These are cryptographic resources such as public keys and
   certificates associated with the entity represented by this card.  A
   CryptoResource object has all properties of the Resource
   (Section 1.5.4) data type, with the following additional definitions:

   *  The @type property value MUST be CryptoResource.

   *  The type property value either is not set, is defined in a future
      RFC or vendor-specific.

   "cryptoKeys": {
     "mykey": {
       "@type": "CryptoResource",
       "uri": "http://www.example.com/keys/jdoe.cer"
     }
   }

                       Figure 26: cryptoKeys example

2.6.2.  directories

   Type: Id[DirectoryResource] (optional).

   These are directory service resources, such as entries in a directory
   or organizational directories for lookup.  A DirectoryResource object
   has all properties of the Resource (Section 1.5.4) data type, with
   the following additional definitions:

   *  The @type property value MUST be DirectoryResource.

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   The type property value MUST be one of the following, or be defined
   in a future RFC or vendor-specific:

   *  directory The resource is a directory service where the entity
      represented by this card is part of.  This typically is an
      organizational directory that also contains associated entities,
      e.g.  co-workers and management in a company directory.

   *  entry The resource is a directory entry of the entity represented
      by this card.  In contrast to the directory type, this is the
      specific URI for the entity _within_ a directory.

   In addition, the DirectoryResource object has the following property:

   *  listAs: UnsignedInt (optional).  This defines the position of this
      directory resource in the list of all DirectoryResource objects
      having the same type in this card.  If set, the listAs value MUST
      be higher than zero.  Applications that display the directories of
      a Card in a list SHOULD order them such that entries with a higher
      property value sort after lower ones.  Multiple directory
      resources MAY have the same listAs property value, or none at all.
      Sorting such entries is implementation-specific.

   "directories": {
     "dir1": {
       "@type": "DirectoryResource",
       "type": "entry",
       "uri": "http://dir.example.com/addrbook/jdoe/Jean%20Dupont.vcf"
     },
     "dir2": {
       "@type": "DirectoryResource",
       "type": "directory",
       "uri": "ldap://ldap.example/o=Example%20Tech,ou=Engineering",
       "pref": 1
     }

                       Figure 27: directories example

2.6.3.  links

   Type: Id[LinkResource] (optional).

   These are links to resources that do not fit any of the other use-
   case specific resource properties.  A LinkResource object has all
   properties of the Resource (Section 1.5.4) data type, with the
   following additional definitions:

   *  The @type property value MUST be LinkResource.

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   The type property value either is not set, or MUST be one of the
   following, or be defined in a future RFC or vendor-specific:

   *  contact The resource is an URI by which the entity represented by
      this card may be contacted, including web forms or other media
      that require user interaction.

   "links": {
     "link3": {
       "@type": "LinkResource",
       "type": "contact",
       "uri": "mailto:contact@example.com",
       "pref": 1
     }
   }

                          Figure 28: links example

2.6.4.  media

   Type: Id[MediaResource] (optional).

   These are media resources such as photographs, avatars, or sounds
   associated with the entity represented by this card.  A MediaResource
   object has all properties of the Resource (Section 1.5.4) data type,
   with the following additional definitions:

   *  The @type property value MUST be MediaResource.

   The type property value must be one of the following, or be defined
   in a future RFC or vendor-specific:

   *  photo The resource is a photograph or avatar.

   *  sound The resource is audio media, e.g.  to specify the proper
      pronunciation of the name property contents.

   *  logo The resource is a graphic image or logo associated with
      entity represented by this card.

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   "media": {
     "res45": {
       "@type": "MediaResource",
       "type": "sound",
       "uri": "CID:JOHNQ.part8.19960229T080000.xyzMail@example.com"
     },
     "res47": {
       "@type": "MediaResource",
       "type": "logo",
       "uri": "http://www.example.com/pub/logos/abccorp.jpg"
     },
     "res1": {
       "@type": "MediaResource",
       "type": "photo",
       "uri": "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAASABIAAD/4..."
     }
   }

                          Figure 29: media example

2.7.  Multilingual properties

2.7.1.  localizations

   Type: String[PatchObject] (optional).

   This property localizes property values in this Card to languages
   other than the main locale.  Its purpose is to provide language-
   specific alternatives to existing values, not to add new values.  In
   other words, a localized Card SHOULD NOT contain more information
   than its non-localized variant.

   The keys in the localizations property object are language tags
   [RFC5646].  The values are patch objects which localize the Card in
   the respective language tag.  The paths in the PatchObject are
   relative to the Card object that includes the localizations property.
   A patch MUST NOT target the localizations property.

   Conceptually, a Card is localized as follows:

   *  Determine the language tag in which this Card should be localized
      in.

   *  If the localizations property includes a key for that language,
      obtain the PatchObject value.  If there is no such key, stop.

   *  Create a copy of the Card, but do not copy the localizations
      property.

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   *  Apply all patches in the PatchObject to the copy of the Card.

   *  Optionally, set the locale property in the copy of the Card.

   *  Use the patched copy of the Card as the localized variant of the
      original Card.

   A patch in the PatchObject may patch a simple-typed property value,
   or a complex type.

   Figure 30 shows how a single String property value is localized in
   the jp locale.

   "locale": "en",
   "addresses": {
     "addr1": {
       "@type": "Address",
       "locality": "Tokyo"
     }
   },
   "localizations": {
     "jp": {
       "addresses/addr1/locality": "東京"
     }
   }

                                 Figure 30

   Figure 31 shows how a complete object property value is localized in
   the en locale.

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   "locale": "ru",
   "name": {
     "@type": "Name",
     "components": [
       {
         "@type": "NameComponent",
         "type": "given",
         "value": "Фёдор"
       },
       {
         "@type": "NameComponent",
         "type": "middle",
         "value": "Михайлович"
       },
       {
         "@type": "NameComponent",
         "type": "surname",
         "value": "Достоевский"
       }
     ]
   },
   "localizations": {
     "en": {
       "name": {
         "@type": "Name",
         "components": [
           {
             "@type": "NameComponent",
             "type": "given",
             "value": "Fyodor"
           },
           {
             "@type": "NameComponent",
             "type": "middle",
             "value": "Mikhailovich"
           },
           {
             "@type": "NameComponent",
             "type": "surname",
             "value": "Dostoevsky"
           }
         ]
       }
     }
   }

                                 Figure 31

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2.8.  Additional properties

2.8.1.  anniversaries

   Type : Id[Anniversary] (optional).

   These are memorable dates and events for the entity represented by
   this card.  An Anniversary object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Anniversary.

   *  type: String (optional).  Specifies the type of the anniversary.
      This RFC predefines the following types, but implementations MAY
      use additional values:

      -  birth: a birthday anniversary

      -  death: a deathday anniversary

      -  wedding: a wedding day anniversary

   *  date: Timestamp|PartialDate (mandatory).

      The date of this anniversary in the Gregorian calendar.  This MUST
      either be a whole or partial calendar date or a complete UTC
      timestamp (see the definition of the Timestamp and PartialDate
      object types below).

   *  place: Address (optional).  An address associated with this
      anniversary, e.g.  the place of birth or death.

   A Timestamp object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Timestamp.

   *  utc: UTCDateTime (mandatory).  Specifies the point in time in UTC
      time.

   A PartialDate object represents a complete or partial calendar date
   in the Gregorian calendar.  It represents either a complete date, or
   a year, or a month in a year, or a day in a month.  It has the
   following properties, of which at least year or month and day MUST be
   set:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be PartialDate.

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   *  year: UnsignedInt (optional).  This is the calendar year.

   *  month: UnsignedInt (optional).  This is the calendar month,
      represented as the integers 1 <= month <= 12.  If this property is
      set then either year or day MUST be set.

   *  day: UnsignedInt (optional).  This is the calendar month day,
      represented as the integers 1 <= day <= 31, depending on the
      validity within the month and year.  If this property is set then
      month MUST be set.

   *  calendarScale: String (optional).  This is the calendar system in
      which this date occurs, in lowercase.  This MUST be either a CLDR-
      registered calendar system name [RFC7529] or a vendor-specific
      value.  The year, month and day still MUST be represented in the
      Gregorian calendar.  Note that for calendar systems with leap
      months, the year property might be required to convert between the
      Gregorian calendar date and the respective calendar system.

   "anniversaries": {
     "k8": {
       "@type": "Anniversary",
       "type": "birth",
       "date": {
         "@type": "PartialDate",
         "year": 1953,
         "month": 4,
         "day": 15
       }
     },
     "k9": {
       "@type": "Anniversary",
       "type": "death",
       "date": {
         "@type": "Timestamp",
         "utc": "1996-10-15T23:10:00Z"
       },
       "place": {
         "@type": "Address",
         "fullAddress": "4445 Tree Street\nNew England, ND 58647\nUSA"
       }
     }
   }

                      Figure 32: anniversaries example

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2.8.2.  keywords

   Type: String[Boolean] (optional).  A set of free-text keywords, also
   known as _tags_.  The set is represented as an object, with each key
   being a keyword.  The boolean value MUST be true.

   "keywords": {
     "internet": true,
     "IETF": true
   }

                        Figure 33: keywords example

2.8.3.  notes

   Type: Id[Note] (optional).

   Free-text notes associated with this card.  A Note object has the
   following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Note.

   *  note: String (mandatory).  The free text value of this note.

   *  created: UTCDateTime (optional).  The date and time when this note
      was created.

   *  author: Author (optional).  The author of this note.

   An Author object has the following properties, of which at least one
   other than @type MUST be defined:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be Author.

   *  name: String (optional).  The name of this author.

   *  uri: String (optional).  A URI value that identifies the author.

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   "notes": {
     "n1": {
       "note": "Open office hours are 1600 to 1715 EST, Mon-Fri",
       "created": "2022-11-23T15:01:32Z",
       "author": {
         "@type": "Author",
         "name": "John"
       }
     }
   }

                          Figure 34: notes example

2.8.4.  personalInfo

   Type: Id[PersonalInfo] (optional).

   Defines personal information about the entity represented by this
   card.  A PersonalInfo object has the following properties:

   *  @type: String (mandatory).  Specifies the type of this object.
      This MUST be PersonalInfo.

   *  type: String (mandatory).  Specifies the type for this personal
      information.  The value MUST be one of the following, or be
      registered in a future RFC or vendor-specific (Section 1.9.1):

      -  expertise: a field of expertise or credential

      -  hobby: a hobby

      -  interest: an interest

   *  value: String (mandatory).  The actual information.  This is free-
      text, but future specifications MAY restrict allowed values
      depending on the type of this PersonalInfo.

   *  level: String (optional).  Indicates the level of expertise, or
      engagement in hobby or interest.  The value MUST be one of the
      following, or be registered in a future RFC or vendor-specific
      (Section 1.9.1): high, medium and low.

   *  listAs: UnsignedInt (optional).  This defines the position of this
      personal information in the list of all PersonalInfo objects
      having the same type in this card.  If set, the listAs value MUST
      be higher than zero.  Applications that display personal
      information entries in a list SHOULD order them such that entries
      with a higher property value sort after lower ones.  Multiple

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      personal information entries MAY have the same listAs property
      value, or none at all.  Sorting such entries is implementation-
      specific.

   *  label: String (optional).  A custom label.  See Section 1.6.2.

   "personalInfo": {
     "pi2": {
       "@type": "PersonalInfo",
       "type": "expertise",
       "value": "chemistry",
       "level": "high"
     },
     "pi1": {
       "@type": "PersonalInfo",
       "type": "hobby",
       "value": "reading",
       "level": "high"
     },
     "pi6": {
       "@type": "PersonalInfo",
       "type": "interest",
       "value": "r&b music",
       "level": "medium"
     }
   }

                      Figure 35: personalInfo example

3.  Implementation Status

   NOTE: Please remove this section and the reference to [RFC7942] prior
   to publication as an RFC.  This section records the status of known
   implementations of the protocol defined by this specification at the
   time of posting of this Internet-Draft, and is based on a proposal
   described in [RFC7942].  The description of implementations in this
   section is intended to assist the IETF in its decision processes in
   progressing drafts to RFCs.  Please note that the listing of any
   individual implementation here does not imply endorsement by the
   IETF.  Furthermore, no effort has been spent to verify the
   information presented here that was supplied by IETF contributors.
   This is not intended as, and must not be construed to be, a catalog
   of available implementations or their features.  Readers are advised
   to note that other implementations may exist.  According to
   [RFC7942], "this will allow reviewers and working groups to assign
   due consideration to documents that have the benefit of running code,
   which may serve as evidence of valuable experimentation and feedback
   that have made the implemented protocols more mature.  It is up to

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   the individual working groups to use this information as they see
   fit".

3.1.  IIT-CNR/Registro.it

   *  Responsible Organization: Institute of Informatics and Telematics
      of National Research Council (IIT-CNR)/Registro.it

   *  Location: https://rdap.pubtest.nic.it/
      (https://rdap.pubtest.nic.it/)

   *  Description: This implementation includes support for RDAP queries
      using data from the public test environment of .it ccTLD.  The
      RDAP server returns responses including Card in place of jCard
      when queries contain the parameter jscard=1.

   *  Level of Maturity: This is an "alpha" test implementation.

   *  Coverage: This implementation includes all of the features
      described in this specification.

   *  Contact Information: Mario Loffredo, mario.loffredo@iit.cnr.it

4.  IANA Considerations

4.1.  Media Type Registration

   This document defines a media type for use with JSContact data
   formatted in JSON.

   Type name:  application

   Subtype name:  jscontact+json

   Required parameters:  type

      The type parameter conveys the type of the JSContact data in the
      body part.  The allowed parameter values correspond to the @type
      property of the JSON-formatted JSContact object in the body.  This
      RFC specifies a single type, but future RFC documents MAY extend
      this list:

      card:  The @type property value of the JSContact object MUST be
         Card.

      The parameter MUST NOT occur more than once.

   Optional parameters:  version

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      The version parameter conveys the version of the JSContact object
      in the body part.  Its value MUST match the value of the version
      property of the JSContact object.

   Encoding considerations:  This is the same as the encoding
      considerations of application/json, as specified in Section 11 of
      [RFC8259].

   Security considerations:  See Section 5 of this document.

   Interoperability considerations:  While JSContact is designed to
      avoid ambiguities as much as possible, when converting objects
      from other contact formats to/from JSContact, it is possible that
      differing representations for the same logical data or ambiguities
      in interpretation might arise.  The semantic equivalence of two
      JSContact objects may be determined differently by different
      applications, for example, where URL values differ in case between
      the two objects.

   Published specification:  TBD

   Applications that use this media type:  Applications that currently
      make use of the text/vcard media type can use this as an
      alternative.

   Fragment identifier considerations:  A JSON Pointer fragment
      identifier may be used, as defined in [RFC6901], Section 6.

   Additional information:  Magic number(s):  N/A

                            File extensions(s):  N/A

                            Macintosh file type code(s):  N/A

   Person & email address to contact for further information:  calsify@i
      etf.org

   Intended usage:  COMMON

   Restrictions on usage:  N/A

   Author:  See the "Author's Address" section of this document.

   Change controller:  IETF

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4.2.  Creation of the "JSContact Properties" Registry

   IANA has created the "JSContact Properties" registry to allow
   interoperability of extensions to JSContact objects.

   This registry follows the Expert Review process ([RFC8126],
   Section 4.5).  If the "Intended Usage" field is common, sufficient
   documentation is required to enable interoperability.  Preliminary
   community review for this registry is optional but strongly
   encouraged.

   A registration can have an intended usage of common, reserved, or
   obsolete.  IANA will list registrations with a common usage
   designation prominently and separately from those with other intended
   usage values.

   A reserved registration reserves a property name without assigning
   semantics to avoid name collisions with future extensions or protocol
   use.

   An obsolete registration denotes a property that is no longer
   expected to be added by up-to-date systems.  A new property has
   probably been defined covering the obsolete property's semantics.

   Every registration MUST define the version of the JSContact
   specification on which the definition of the newly registered,
   updated or obsoleted item is based on.  This typically is the latest
   specification version that is in effect when the property gets
   registered.  The version MUST be one of the allowed values of the
   @version property in the JSContact Enum Value registry (see Table 6).

   The JSContact property registration procedure is not a formal
   standards process but rather an administrative procedure intended to
   allow community comment and check it is coherent without excessive
   time delay.  It is designed to encourage vendors to document and
   register new properties they add for use cases not covered by the
   original specification, leading to increased interoperability.

4.2.1.  Preliminary Community Review

   Notice of a potential new registration SHOULD be sent to the Calext
   mailing list <calsify@ietf.org> for review.  This mailing list is
   appropriate to solicit community feedback on a proposed new property.

   Property registrations must be marked with their intended use:
   "common", "reserved", or "obsolete".

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   The intent of the public posting to this list is to solicit comments
   and feedback on the choice of the property name, the unambiguity of
   the specification document, and a review of any interoperability or
   security considerations.  The submitter may submit a revised
   registration proposal or abandon the registration completely at any
   time.

4.2.2.  Submit Request to IANA

   Registration requests can be sent to <iana@iana.org>.

4.2.3.  Designated Expert Review

   The primary concern of the designated expert (DE) is preventing name
   collisions and encouraging the submitter to document security and
   privacy considerations.  For a common-use registration, the DE is
   expected to confirm that suitable documentation, as described in
   Section 4.6 of [RFC8126], is available to ensure interoperability.
   That documentation will usually be in an RFC, but simple definitions
   are likely to use a web/wiki page, and if a sentence or two is deemed
   sufficient, it could be described in the registry itself.  The DE
   should also verify that the property name does not conflict with work
   that is active or already published within the IETF.  A published
   specification is not required for reserved or obsolete registrations.

   The DE will either approve or deny the registration request and
   publish a notice of the decision to the Calext WG mailing list or its
   successor, as well as inform IANA.  A denial notice must be justified
   by an explanation, and, in the cases where it is possible, concrete
   suggestions on how the request can be modified so as to become
   acceptable should be provided.

4.2.4.  Change Procedures

   Once a JSContact property has been published by IANA, the change
   controller may request a change to its definition.  The same
   procedure that would be appropriate for the original registration
   request is used to process a change request.

   JSContact property registrations may not be deleted; properties that
   are no longer believed appropriate for use can be declared obsolete
   by a change to their "intended usage" field; such properties will be
   clearly marked in the IANA registry.

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   Significant changes to a JSContact property's definition should be
   requested only when there are serious omissions or errors in the
   published specification, as such changes may cause interoperability
   issues.  When review is required, a change request may be denied if
   it renders entities that were valid under the previous definition
   invalid under the new definition.

   The owner of a JSContact property may pass responsibility to another
   person or agency by informing IANA; this can be done without
   discussion or review.

4.2.5.  "JSContact Properties" Registry Template

   Property Name:  This is the name of the property.  The property name
      MUST NOT already be registered for any of the object types listed
      in the "Property Context" field of this registration.  Other
      object types MAY already have registered a different property with
      the same name; however, the same name SHOULD only be used when the
      semantics are analogous.

   Property Type:  This is the type of this property, using type
      signatures, as specified in Section 1.4.  The property type MUST
      be registered in the "JSContact Types" registry.

   Property Context:  This is a comma-separated list of JSContact object
      types this property is allowed on.

   Reference or Description:  This is a brief description or RFC number
      and section reference where the property is specified (omitted for
      "reserved" property names).  This must include references to all
      RFC documents where this property is introduced or updated.

   Intended Usage:  This may be "common", "reserved", or "obsolete".

   Since Version:  This defines the JSContact version on which this
      property definition is based on.  The version MUST be one of the
      allowed values of the @version property in the JSContact Enum
      Value registry (see Table 6).

   Until Version:  This defines the JSContact version after which this
      property got obsoleted and MUST NOT be used in later versions.
      The Until Version value either MUST NOT be set, or be one of the
      allowed values of the @version property in the JSContact Enum
      Value registry (see Table 6).

   Change Controller:  This is who may request a change to this entry's
      definition (IETF for RFCs from the IETF stream).

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4.2.6.  Initial Contents for the "JSContact Properties" Registry

   The following table lists the initial common usage entries of the
   "JSContact Properties" registry.  The Since Version for all
   properties is 1.0.  The Until Version for all properties is not set.
   All RFC section references are for this document.  The change
   controller for all these properties is IETF.

   +========================+==================================+=========================+============+
   |Property Name           |Property Type                     |Property Context         |Reference or|
   |                        |                                  |                         |Description |
   +========================+==================================+=========================+============+
   |@type                   |String                            |Address, Anniversary,    |Section     |
   |                        |                                  |Author, Card,            |2.5.1,      |
   |                        |                                  |CalendarResource,        |Section     |
   |                        |                                  |ContactChannelPreference,|2.8.1,      |
   |                        |                                  |CryptoResource,          |Section     |
   |                        |                                  |DirectoryResource,       |2.1.1,      |
   |                        |                                  |EmailAddress,            |Section     |
   |                        |                                  |LanguagePreference,      |2.4.1,      |
   |                        |                                  |LinkResource,            |Section     |
   |                        |                                  |MediaResource, Name,     |2.3.4,      |
   |                        |                                  |NameComponent, NickName, |Section     |
   |                        |                                  |Note, OnlineService,     |2.6.1,      |
   |                        |                                  |Organization, OrgUnit,   |Section     |
   |                        |                                  |PartialDate,PersonalInfo,|2.6.2,      |
   |                        |                                  |Phone, Pronouns,         |Section     |
   |                        |                                  |Relation, Resource,      |2.3.1,      |
   |                        |                                  |SchedulingAddress,       |Section     |
   |                        |                                  |SpeakToAs,               |2.3.5,      |
   |                        |                                  |StreetComponent,         |Section     |
   |                        |                                  |Timestamp, Title         |2.6.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.2.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.2.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.8.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.3.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.2.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.8.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.3.3,      |

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   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.2.5,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.1.8,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.4.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.2.6       |
   +------------------------+----------------------------------+-------------------------+------------+
   |@version                |String                            |Card                     |Section     |
   |                        |                                  |                         |2.1.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |address                 |String                            |EmailAddress             |Section     |
   |                        |                                  |                         |2.3.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |addresses               |Id[Address]                       |Card                     |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |anniversaries           |Id[Anniversary]                   |Card                     |Section     |
   |                        |                                  |                         |2.8.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |author                  |Author                            |Note                     |Section     |
   |                        |                                  |                         |2.8.3       |
   +------------------------+----------------------------------+-------------------------+------------+
   |calendars               |Id[CalendarResource]              |Card                     |Section     |
   |                        |                                  |                         |2.4.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |calendarScale           |String                            |PartialDate              |Section     |
   |                        |                                  |                         |2.8.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |components              |NameComponent[]                   |Name                     |Section     |
   |                        |                                  |                         |2.2.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |contexts                |String[Boolean]                   |Address, NickName,       |Section     |
   |                        |                                  |Pronouns, EmailAddress,  |1.6.1,      |
   |                        |                                  |OnlineService, Phone,    |Section     |
   |                        |                                  |ContactChannelPreference,|2.5.1,      |
   |                        |                                  |LanguagePreference,      |Section     |
   |                        |                                  |CalendarResource,        |2.2.3,      |
   |                        |                                  |CryptoResource,          |Section     |
   |                        |                                  |DirectoryResource,       |2.2.5,      |
   |                        |                                  |LinkResource,            |Section     |
   |                        |                                  |MediaResource,           |2.3.1,      |
   |                        |                                  |Organization,            |Section     |
   |                        |                                  |SchedulingAddress        |2.3.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.3.3,      |
   |                        |                                  |                         |Section     |

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   |                        |                                  |                         |2.3.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.3.5,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |1.5.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.4.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.2.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.4.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |coordinates             |String                            |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |country                 |String                            |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |countryCode             |String                            |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |created                 |UTCDateTime                       |Card, Note               |Section     |
   |                        |                                  |                         |2.1.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.8.3       |
   +------------------------+----------------------------------+-------------------------+------------+
   |date                    |Timestamp|PartialDate             |Anniversary              |Section     |
   |                        |                                  |                         |2.8.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |day                     |UnsignedInt                       |PartialDate              |Section     |
   |                        |                                  |                         |2.8.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |directories             |Id[DirectoryResource]             |Card                     |Section     |
   |                        |                                  |                         |2.6.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |emails                  |Id[EmailAddress]                  |Card                     |Section     |
   |                        |                                  |                         |2.3.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |features                |String[Boolean]                   |Phone                    |Section     |
   |                        |                                  |                         |2.3.3       |

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   +------------------------+----------------------------------+-------------------------+------------+
   |fullAddress             |String                            |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |fullName                |String                            |Card                     |Section     |
   |                        |                                  |                         |2.2.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |grammaticalGender       |String                            |SpeakToAs                |Section     |
   |                        |                                  |                         |2.2.5       |
   +------------------------+----------------------------------+-------------------------+------------+
   |keywords                |String[Boolean]                   |Card                     |Section     |
   |                        |                                  |                         |2.8.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |kind                    |String                            |Card                     |Section     |
   |                        |                                  |                         |2.1.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |label                   |String                            |EmailAddress,            |Section     |
   |                        |                                  |OnlineService, Phone,    |1.6.2,      |
   |                        |                                  |CalendarResource,        |Section     |
   |                        |                                  |CryptoResource,          |2.3.1,      |
   |                        |                                  |DirectoryResource,       |Section     |
   |                        |                                  |LinkResource,            |2.3.2,      |
   |                        |                                  |MediaResource,           |Section     |
   |                        |                                  |PersonalInfo,            |2.3.3,      |
   |                        |                                  |SchedulingAddress        |Section     |
   |                        |                                  |                         |1.5.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.4.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.8.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.4.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |level                   |String                            |PersonalInfo             |Section     |
   |                        |                                  |                         |2.8.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |links                   |Id[LinkResource]                  |Card                     |Section     |
   |                        |                                  |                         |2.6.3       |
   +------------------------+----------------------------------+-------------------------+------------+
   |listAs                  |UnsignedInt                       |DirectoryResource,       |Section     |

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   |                        |                                  |PersonalInfo             |2.6.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.8.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |locale                  |String                            |Card                     |Section     |
   |                        |                                  |                         |2.1.5       |
   +------------------------+----------------------------------+-------------------------+------------+
   |locality                |String                            |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |localizations           |String[PatchObject]               |Card                     |Section     |
   |                        |                                  |                         |2.7.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |media                   |Id[MediaResource]                 |Card                     |Section     |
   |                        |                                  |                         |2.6.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |mediaType               |String                            |CalendarResource,        |Section     |
   |                        |                                  |CryptoResource,          |1.5.4,      |
   |                        |                                  |DirectoryResource,       |Section     |
   |                        |                                  |LinkResource,            |2.4.1,      |
   |                        |                                  |MediaResource            |Section     |
   |                        |                                  |                         |2.6.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |members                 |String[Boolean]                   |Card                     |Section     |
   |                        |                                  |                         |2.1.6       |
   +------------------------+----------------------------------+-------------------------+------------+
   |month                   |UnsignedInt                       |PartialDate              |Section     |
   |                        |                                  |                         |2.8.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |name                    |Name                              |Card                     |Section     |
   |                        |                                  |                         |2.2.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |name                    |String                            |Author, NickName,        |Section     |
   |                        |                                  |Organization, OrgUnit,   |2.8.3,      |
   |                        |                                  |Title                    |Section     |
   |                        |                                  |                         |2.2.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.2.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.2.6       |
   +------------------------+----------------------------------+-------------------------+------------+
   |nickNames               |Id[NickName]                      |Card                     |Section     |

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   |                        |                                  |                         |2.2.3       |
   +------------------------+----------------------------------+-------------------------+------------+
   |note                    |String                            |Note                     |Section     |
   |                        |                                  |                         |2.8.3       |
   +------------------------+----------------------------------+-------------------------+------------+
   |notes                   |Id[Note]                          |Card                     |Section     |
   |                        |                                  |                         |2.8.3       |
   +------------------------+----------------------------------+-------------------------+------------+
   |number                  |String                            |Phone                    |Section     |
   |                        |                                  |                         |2.3.3       |
   +------------------------+----------------------------------+-------------------------+------------+
   |onlineServices          |Id[OnlineService]                 |Card                     |Section     |
   |                        |                                  |                         |2.3.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |organization            |String                            |Title                    |Section     |
   |                        |                                  |                         |2.2.6       |
   +------------------------+----------------------------------+-------------------------+------------+
   |organizations           |Id[Organization]                  |Card                     |Section     |
   |                        |                                  |                         |2.2.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |personalInfo            |Id[PersonalInfo]                  |Card                     |Section     |
   |                        |                                  |                         |2.8.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |phones                  |Id[Phone]                         |Card                     |Section     |
   |                        |                                  |                         |2.3.3       |
   +------------------------+----------------------------------+-------------------------+------------+
   |place                   |Address                           |Anniversary              |Section     |
   |                        |                                  |                         |2.8.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |postcode                |String                            |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |pref                    |UnsignedInt                       |Address, NickName,       |Section     |
   |                        |                                  |Pronouns, EmailAddress,  |1.6.3,      |
   |                        |                                  |OnlineService, Phone,    |Section     |
   |                        |                                  |ContactChannelPreference,|2.5.1,      |
   |                        |                                  |LanguagePreference,      |Section     |
   |                        |                                  |CalendarResource,        |2.2.3,      |
   |                        |                                  |CryptoResource,          |Section     |
   |                        |                                  |DirectoryResource,       |2.2.5,      |
   |                        |                                  |LinkResource,            |Section     |
   |                        |                                  |MediaResource,           |2.3.1,      |
   |                        |                                  |SchedulingAddress        |Section     |
   |                        |                                  |                         |2.3.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.3.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.3.4,      |

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   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.3.5,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |1.5.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.4.1Section|
   |                        |                                  |                         |2.6.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.4.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |preferredContactChannels|String[ContactChannelPreference[]]|Card                     |Section     |
   |                        |                                  |                         |2.3.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |preferredLanguages      |String[LanguagePreference[]]      |Card                     |Section     |
   |                        |                                  |                         |2.3.5       |
   +------------------------+----------------------------------+-------------------------+------------+
   |prodId                  |String                            |Card                     |Section     |
   |                        |                                  |                         |2.1.7       |
   +------------------------+----------------------------------+-------------------------+------------+
   |pronouns                |Id[Pronouns]                      |SpeakToAs                |Section     |
   |                        |                                  |                         |2.2.5       |
   +------------------------+----------------------------------+-------------------------+------------+
   |pronouns                |String                            |Pronouns                 |Section     |
   |                        |                                  |                         |2.2.5       |
   +------------------------+----------------------------------+-------------------------+------------+
   |rank                    |UnsignedInt                       |NameComponent            |Section     |
   |                        |                                  |                         |2.2.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |region                  |String                            |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |relatedTo               |String[Relation]                  |Card                     |Section     |
   |                        |                                  |                         |2.1.8       |
   +------------------------+----------------------------------+-------------------------+------------+
   |relation                |String[Boolean]                   |Relation                 |Section     |
   |                        |                                  |                         |2.1.8       |
   +------------------------+----------------------------------+-------------------------+------------+
   |schedulingAddresses     |Id[SchedulingAddress]             |Card                     |Section     |
   |                        |                                  |                         |2.4.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |service                 |String                            |OnlineService            |Section     |
   |                        |                                  |                         |2.3.2       |

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   +------------------------+----------------------------------+-------------------------+------------+
   |sortAs                  |String[String]                    |Name                     |Section     |
   |                        |                                  |                         |2.2.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |sortAs                  |String                            |Organization, OrgUnit    |Section     |
   |                        |                                  |                         |2.2.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |speakToAs               |SpeakToAs                         |Card                     |Section     |
   |                        |                                  |                         |2.2.5       |
   +------------------------+----------------------------------+-------------------------+------------+
   |street                  |StreetComponent[]                 |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |timeZone                |String                            |Address                  |Section     |
   |                        |                                  |                         |2.5.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |titles                  |Id[Title]                         |Card                     |Section     |
   |                        |                                  |                         |2.2.6       |
   +------------------------+----------------------------------+-------------------------+------------+
   |type                    |String                            |Anniversary,             |Section     |
   |                        |                                  |NameComponent, Title,    |2.8.1,      |
   |                        |                                  |CalendarResource,        |Section     |
   |                        |                                  |CryptoResource,          |2.2.2,      |
   |                        |                                  |DirectoryResource,       |Section     |
   |                        |                                  |LinkResource,            |2.2.6,      |
   |                        |                                  |MediaResource,           |Section     |
   |                        |                                  |OnlineService,           |1.5.4,      |
   |                        |                                  |StreetComponent,         |Section     |
   |                        |                                  |PersonalInfo             |2.4.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.3.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.5.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.8.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |uid                     |String                            |Card                     |Section     |
   |                        |                                  |                         |2.1.9       |
   +------------------------+----------------------------------+-------------------------+------------+
   |units                   |OrgUnit[]                         |Organization             |Section     |

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   |                        |                                  |                         |2.2.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |updated                 |UTCDateTime                       |Card                     |Section     |
   |                        |                                  |                         |2.1.10      |
   +------------------------+----------------------------------+-------------------------+------------+
   |uri                     |String                            |Author, CalendarResource,|Section     |
   |                        |                                  |CryptoResource,          |2.8.3,      |
   |                        |                                  |DirectoryResource,       |Section     |
   |                        |                                  |LinkResource,            |1.5.4,      |
   |                        |                                  |MediaResource,           |Section     |
   |                        |                                  |SchedulingAddress        |2.4.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.2,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.3,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.6.4,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.4.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |user                    |String                            |OnlineService            |Section     |
   |                        |                                  |                         |2.3.2       |
   +------------------------+----------------------------------+-------------------------+------------+
   |utc                     |UTCDateTime                       |Timestamp                |Section     |
   |                        |                                  |                         |2.8.1       |
   +------------------------+----------------------------------+-------------------------+------------+
   |value                   |String                            |NameComponent,           |Section     |
   |                        |                                  |StreetComponent,         |2.2.2,      |
   |                        |                                  |PersonalInfo             |Section     |
   |                        |                                  |                         |2.5.1,      |
   |                        |                                  |                         |Section     |
   |                        |                                  |                         |2.8.4       |
   +------------------------+----------------------------------+-------------------------+------------+
   |year                    |UnsignedInt                       |PartialDate              |Section     |
   |                        |                                  |                         |2.8.1       |
   +------------------------+----------------------------------+-------------------------+------------+

      Table 1: Initial Contents of the "JSContact Properties" Registry

   The following table lists the initial reserved usage entries of the
   "JSContact Properties" registry.  All RFC section references are for
   this document.  The change controller for all these properties is
   IETF.

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   +===============+============+============+==============+==========+
   | Property      | Property   | Property   | Reference or | Intended |
   | Name          | Type       | Context    | Description  | Usage    |
   +===============+============+============+==============+==========+
   | extra         | not        | not        | Section 1.10 | reserved |
   |               | applicable | applicable |              |          |
   +---------------+------------+------------+--------------+----------+

      Table 2: Initial Contents of the "JSContact Properties" Registry

4.3.  Creation of the "JSContact Types" Registry

   IANA has created the "JSContact Types" registry to avoid name
   collisions and provide a complete reference for all data types used
   for JSContact property values.  The registration process is the same
   as for the "JSContact Properties" registry, as defined in
   Section 4.2.

4.3.1.  "JSContact Types" Registry Template

   Type Name:  the name of the type

   Reference or Description:  a brief description or RFC number and
      section reference where the Type is specified (may be omitted for
      "reserved" type names)

   Intended Usage:  common, reserved, or obsolete

   Since Version:  This defines the JSContact version on which this type
      definition is based on.  The version MUST be one of the allowed
      values of the @version property in the JSContact Enum Value
      registry (see Table 6).

   Until Version:  This defines the JSContact version after which this
      type definition got obsoleted and MUST NOT be used in later
      versions.  The Until Version value either MUST be not set, or one
      of the allowed values of the @version property in the JSContact
      Enum Value registry (see Table 6).

   Change Controller:  who may request a change to this entry's
      definition (IETF for RFCs from the IETF stream)

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4.3.2.  Initial Contents for the "JSContact Types" Registry

   The following table lists the initial common usage entries of the
   JSContact Types registry.  The Since Version for all types is 1.0.
   The Until Version for all types is not set.  All RFC section
   references are for this document.  The change controller for all
   these properties is IETF.

   +==========================+==========================+
   | Type Name                | Reference or Description |
   +==========================+==========================+
   | Address                  | Section 2.5.1            |
   +--------------------------+--------------------------+
   | Anniversary              | Section 2.8.1            |
   +--------------------------+--------------------------+
   | Author                   | Section 2.8.3            |
   +--------------------------+--------------------------+
   | Boolean                  | Section 1.4              |
   +--------------------------+--------------------------+
   | CalendarResource         | Section 2.4.1            |
   +--------------------------+--------------------------+
   | Card                     | Section 2                |
   +--------------------------+--------------------------+
   | ContactChannelPreference | Section 2.3.4            |
   +--------------------------+--------------------------+
   | CryptoResource           | Section 2.6.1            |
   +--------------------------+--------------------------+
   | DirectoryResource        | Section 2.6.2            |
   +--------------------------+--------------------------+
   | EmailAddress             | Section 2.3.1            |
   +--------------------------+--------------------------+
   | Id                       | Section 1.5.1            |
   +--------------------------+--------------------------+
   | Int                      | Section 1.5.2            |
   +--------------------------+--------------------------+
   | LanguagePreference       | Section 2.3.5            |
   +--------------------------+--------------------------+
   | LinkResource             | Section 2.6.3            |
   +--------------------------+--------------------------+
   | MediaResource            | Section 2.6.4            |
   +--------------------------+--------------------------+
   | Name                     | Section 2.2.2            |
   +--------------------------+--------------------------+
   | NameComponent            | Section 2.2.2            |
   +--------------------------+--------------------------+
   | NickName                 | Section 2.2.3            |
   +--------------------------+--------------------------+
   | Note                     | Section 2.8.3            |

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   +--------------------------+--------------------------+
   | OnlineService            | Section 2.3.2            |
   +--------------------------+--------------------------+
   | Organization             | Section 2.2.4            |
   +--------------------------+--------------------------+
   | OrgUnit                  | Section 2.2.4            |
   +--------------------------+--------------------------+
   | PartialDate              | Section 2.8.1            |
   +--------------------------+--------------------------+
   | PersonalInfo             | Section 2.8.4            |
   +--------------------------+--------------------------+
   | Phone                    | Section 2.3.3            |
   +--------------------------+--------------------------+
   | Pronouns                 | Section 2.2.5            |
   +--------------------------+--------------------------+
   | Relation                 | Section 2.1.8            |
   +--------------------------+--------------------------+
   | SchedulingAddress        | Section 2.4.2            |
   +--------------------------+--------------------------+
   | SpeakToAs                | Section 2.2.5            |
   +--------------------------+--------------------------+
   | StreetComponent          | Section 2.5.1            |
   +--------------------------+--------------------------+
   | Timestamp                | Section 2.8.1            |
   +--------------------------+--------------------------+
   | Title                    | Section 2.2.6            |
   +--------------------------+--------------------------+
   | UnsignedInt              | Section 1.5.2            |
   +--------------------------+--------------------------+
   | UTCDateTime              | Section 1.5.5            |
   +--------------------------+--------------------------+

      Table 3: Initial Contents of the "JSContact Types"
                           Registry

   The following table lists the initial reserved usage entries of the
   JSContact Types registry.  All types are for version 1.0.  All RFC
   section references are for this document.  The change controller for
   all these properties is IETF.

   +===========+==========================+
   | Type Name | Reference or Description |
   +===========+==========================+
   | Resource  | Section 1.5.4            |
   +-----------+--------------------------+

       Table 4: Initial Contents of the
          "JSContact Types" Registry

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4.4.  Creation of the "JSContact Enum Values" Registry

   IANA has created the "JSContact Enum Values" registry to allow
   interoperable extension of semantics for properties with enumerable
   values.  Each such property will have a subregistry of allowed
   values.  The registration process for a new enum value or adding a
   new enumerable property is the same as for the "JSContact Properties"
   registry, as defined in Section 4.2.

4.4.1.  "JSContact Enum Values" Registry Property Template

   This template is for adding a subregistry for a new enumerable
   property to the "JSContact Enum" registry.

   Property Name:  These are the name(s) of the property or properties
      where these values may be used.  This MUST be registered in the
      "JSContact Properties" registry.

   Context:  This is the list of allowed object types where the property
      or properties may appear, as registered in the "JSContact
      Properties" registry.  This disambiguates where there may be two
      distinct properties with the same name in different contexts.

   Since Version:  This defines the JSContact version on which this enum
      value definition is based on.  The version MUST be one of the
      allowed values of the @version property in the JSContact Enum
      Value registry (see Table 6).

   Until Version:  This defines the JSContact version after which this
      enum value definition got obsoleted and MUST NOT be used in later
      versions.  The Until Version value either MUST be not set, or one
      of the allowed values of the @version property in the JSContact
      Enum Value registry (see Table 6).

   Change Controller:  (IETF for properties defined in RFCs from the
      IETF stream).

   Initial Contents:  This is the initial list of defined values for
      this enum, using the template defined in Section 4.4.2.  A
      subregistry will be created with these values for this property
      name/context tuple.

4.4.2.  "JSContact Enum Values" Registry Value Template

   This template is for adding a new enum value to a subregistry in the
   JSContact Enum registry.

   Enum Value:  The verbatim value of the enum

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   Reference or Description:  A brief description or RFC number and
      section reference for the semantics of this value

   Since Version:  The JSContact version on which the enum value
      definition is based on.  The version MUST be one of the allowed
      values of the @version property in the JSContact Enum Value
      registry (see Table 6).

   Until Version:  The JSContact version after which this enum value got
      obsoleted and MUST NOT be used in later versions.  The Until
      Version value either MUST be not set, or one of the allowed values
      of the @version property in the JSContact Enum Value registry (see
      Table 6).

4.4.3.  Initial Contents for the "JSContact Enum Values" Registry

   For each subregistry created in this section, all RFC section
   references are for this document.  For all entries, the Since Version
   is 1.0, the Until Version is not set, the Change Controller is IETF.

   Property Name:      kind
   Context:            Card
   Initial Contents: 
                       +=============+==========================+
                       | Enum Value  | Reference or Description |
                       +=============+==========================+
                       | individual  | Section 2.1.4            |
                       +-------------+--------------------------+
                       | group       | Section 2.1.4            |
                       +-------------+--------------------------+
                       | org         | Section 2.1.4            |
                       +-------------+--------------------------+
                       | location    | Section 2.1.4            |
                       +-------------+--------------------------+
                       | device      | Section 2.1.4            |
                       +-------------+--------------------------+
                       | application | Section 2.1.4            |
                       +-------------+--------------------------+

                           Table 5: JSContact Enum Values for
                                  kind (Context: Card)

   Property Name:      @version
   Context:            Card
   Initial Contents: 

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                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | 1          | Section 2.1.2            |
                       +------------+--------------------------+

                           Table 6: JSContact Enum Values for
                                @version (Context: Card)

   Property Name:      contexts
   Context:            NickName, Pronouns, EmailAddress, OnlineService,
                       Phone, ContactChannelPreference,
                       LanguagePreference, CalendarResource,
                       CryptoResource, DirectoryResource, LinkResource,
                       MediaResource, SchedulingAddress
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | private    | Section 1.6.1            |
                       +------------+--------------------------+
                       | work       | Section 1.6.1            |
                       +------------+--------------------------+

                           Table 7: JSContact Enum Values for
                              contexts (Context: NickName,
                                Pronouns, EmailAddress,
                                 OnlineService, Phone,
                               ContactChannelPreference,
                         LanguagePreference, CalendarResource,
                           CryptoResource, DirectoryResource,
                              LinkResource, MediaResource,
                                   SchedulingAddress)

   Property Name:      contexts
   Context:            Address
   Initial Contents: 

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                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | private    | Section 1.6.1            |
                       +------------+--------------------------+
                       | work       | Section 1.6.1            |
                       +------------+--------------------------+
                       | billing    | Section 2.5.1            |
                       +------------+--------------------------+
                       | delivery   | Section 2.5.1            |
                       +------------+--------------------------+

                           Table 8: JSContact Enum Values for
                              contexts (Context: Address)

   Property Name:      features
   Context:            Phone
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | voice      | Section 2.3.3            |
                       +------------+--------------------------+
                       | fax        | Section 2.3.3            |
                       +------------+--------------------------+
                       | pager      | Section 2.3.3            |
                       +------------+--------------------------+
                       | text       | Section 2.3.3            |
                       +------------+--------------------------+
                       | cell       | Section 2.3.3            |
                       +------------+--------------------------+
                       | textphone  | Section 2.3.3            |
                       +------------+--------------------------+
                       | video      | Section 2.3.3            |
                       +------------+--------------------------+

                           Table 9: JSContact Enum Values for
                               features (Context: Phone)

   Property Name:      type
   Context:            StreetComponent
   Initial Contents: 

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                       +===============+==========================+
                       | Enum Value    | Reference or Description |
                       +===============+==========================+
                       | name          | Section 2.5.1            |
                       +---------------+--------------------------+
                       | number        | Section 2.5.1            |
                       +---------------+--------------------------+
                       | apartment     | Section 2.5.1            |
                       +---------------+--------------------------+
                       | room          | Section 2.5.1            |
                       +---------------+--------------------------+
                       | extension     | Section 2.5.1            |
                       +---------------+--------------------------+
                       | direction     | Section 2.5.1            |
                       +---------------+--------------------------+
                       | building      | Section 2.5.1            |
                       +---------------+--------------------------+
                       | floor         | Section 2.5.1            |
                       +---------------+--------------------------+
                       | postOfficeBox | Section 2.5.1            |
                       +---------------+--------------------------+
                       | separator     | Section 2.5.1            |
                       +---------------+--------------------------+
                       | unknown       | Section 2.5.1            |
                       +---------------+--------------------------+

                         Table 10: JSContact Enum Values for type
                                (Context: StreetComponent)

   Property Name:      type
   Context:            NameComponent
   Initial Contents: 

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                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | prefix     | Section 2.2.2            |
                       +------------+--------------------------+
                       | given      | Section 2.2.2            |
                       +------------+--------------------------+
                       | surname    | Section 2.2.2            |
                       +------------+--------------------------+
                       | middle     | Section 2.2.2            |
                       +------------+--------------------------+
                       | suffix     | Section 2.2.2            |
                       +------------+--------------------------+
                       | separator  | Section 2.2.2            |
                       +------------+--------------------------+

                          Table 11: JSContact Enum Values for
                             type (Context: NameComponent)

   Property Name:      type
   Context:            Title
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | title      | Section 2.2.6            |
                       +------------+--------------------------+
                       | role       | Section 2.2.6            |
                       +------------+--------------------------+

                          Table 12: JSContact Enum Values for
                                 type (Context: Title)

   Property Name:      grammaticalGender
   Context:            SpeakToAs
   Initial Contents: 

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                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | animate    | Section 2.2.5            |
                       +------------+--------------------------+
                       | female     | Section 2.2.5            |
                       +------------+--------------------------+
                       | inanimate  | Section 2.2.5            |
                       +------------+--------------------------+
                       | male       | Section 2.2.5            |
                       +------------+--------------------------+
                       | neuter     | Section 2.2.5            |
                       +------------+--------------------------+

                          Table 13: JSContact Enum Values for
                               type (Context: SpeakToAs)

   Property Name:      preferredContactChannels
   Context:            Card
   Initial Contents: 
                       +================+==========================+
                       | Enum Value     | Reference or Description |
                       +================+==========================+
                       | addresses      | Section 2.3.4            |
                       +----------------+--------------------------+
                       | emails         | Section 2.3.4            |
                       +----------------+--------------------------+
                       | onlineServices | Section 2.3.4            |
                       +----------------+--------------------------+
                       | phones         | Section 2.3.4            |
                       +----------------+--------------------------+

                            Table 14: JSContact Enum Values for
                          preferredContactChannels (Context: Card)

   Property Name:      type
   Context:            CalendarResource
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | calendar   | Section 2.4.1            |
                       +------------+--------------------------+
                       | freeBusy   | Section 2.4.1            |
                       +------------+--------------------------+

                          Table 15: JSContact Enum Values for
                            type (Context: CalendarResource)

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   Property Name:      type
   Context:            DirectoryResource
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | directory  | Section 2.6.2            |
                       +------------+--------------------------+
                       | entry      | Section 2.6.2            |
                       +------------+--------------------------+

                          Table 16: JSContact Enum Values for
                           type (Context: DirectoryResource)

   Property Name:      type
   Context:            LinkResource
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | contact    | Section 2.6.3            |
                       +------------+--------------------------+

                          Table 17: JSContact Enum Values for
                              type (Context: LinkResource)

   Property Name:      type
   Context:            MediaResource
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | photo      | Section 2.6.4            |
                       +------------+--------------------------+
                       | sound      | Section 2.6.4            |
                       +------------+--------------------------+
                       | logo       | Section 2.6.4            |
                       +------------+--------------------------+

                          Table 18: JSContact Enum Values for
                             type (Context: MediaResource)

   Property Name:      type
   Context:            Anniversary
   Initial Contents: 

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                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | birth      | Section 2.8.1            |
                       +------------+--------------------------+
                       | death      | Section 2.8.1            |
                       +------------+--------------------------+
                       | wedding    | Section 2.8.1            |
                       +------------+--------------------------+

                          Table 19: JSContact Enum Values for
                              type (Context: Anniversary)

   Property Name:      type
   Context:            OnlineService
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | impp       | Section 2.3.2            |
                       +------------+--------------------------+
                       | uri        | Section 2.3.2            |
                       +------------+--------------------------+
                       | username   | Section 2.3.2            |
                       +------------+--------------------------+

                          Table 20: JSContact Enum Values for
                             type (Context: OnlineService)

   Property Name:      type
   Context:            PersonalInfo
   Initial Contents: 
                       +============+==========================+
                       | Enum Value | Reference or Description |
                       +============+==========================+
                       | expertise  | Section 2.8.4            |
                       +------------+--------------------------+
                       | hobby      | Section 2.8.4            |
                       +------------+--------------------------+
                       | interest   | Section 2.8.4            |
                       +------------+--------------------------+

                          Table 21: JSContact Enum Values for
                              type (Context: PersonalInfo)

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5.  Security Considerations

   Contact information is very privacy sensitive.  It can reveal the
   identity, location and credentials information, employment status,
   interests and hobbies, and social network of a user.  Its
   transmission and storage must be done carefully to protect it from
   possible threats, such as eavesdropping, replay, message insertion,
   deletion, modification, and on-path attacks.

   The data being stored and transmitted may be used in systems with
   real-world consequences.  For example, a malicious actor might
   provide JSContact data that uses the name of another person but
   insert their contact details to impersonate the unknown victim.  Such
   systems must be careful to authenticate all data they receive to
   prevent them from being subverted and ensure the change comes from an
   authorized entity.

   This document only defines the data format; such considerations are
   primarily the concern of the API or method of storage and
   transmission of such files.

5.1.  JSON Parsing

   The security considerations of [RFC8259] apply to the use of JSON as
   the data interchange format.

   As for any serialization format, parsers need to thoroughly check the
   syntax of the supplied data.  JSON uses opening and closing tags for
   several types and structures, and it is possible that the end of the
   supplied data will be reached when scanning for a matching closing
   tag; this is an error condition, and implementations need to stop
   scanning at the end of the supplied data.

   JSON also uses a string encoding with some escape sequences to encode
   special characters within a string.  Care is needed when processing
   these escape sequences to ensure that they are fully formed before
   the special processing is triggered, with special care taken when the
   escape sequences appear adjacent to other (non-escaped) special
   characters or adjacent to the end of data (as in the previous
   paragraph).

   If parsing JSON into a non-textual structured data format,
   implementations may need to allocate storage to hold JSON string
   elements.  Since JSON does not use explicit string lengths, the risk
   of denial of service due to resource exhaustion is small, but
   implementations may still wish to place limits on the size of
   allocations they are willing to make in any given context, to avoid
   untrusted data causing excessive memory allocation.

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5.2.  URI Values

   Several JSContact properties contain URIs as values, and processing
   these properties requires extra care.  Section 7 of [RFC3986]
   discusses security risks related to URIs.

   Fetching remote resources carries inherent risks.  Connections must
   only be allowed on well-known ports, using allowed protocols
   (generally, just HTTP/HTTPS on their default ports).  The URL must be
   resolved externally and not allowed to access internal resources.
   Connecting to an external source reveals IP (and therefore often
   location) information.

   A maliciously constructed JSContact object may contain a very large
   number of URIs.  In the case of published address books with a large
   number of subscribers, such objects could be widely distributed.
   Implementations should be careful to limit the automatic fetching of
   linked resources to reduce the risk of this being an amplification
   vector for a denial-of-service attack.

6.  References

6.1.  Normative References

   [RFC1034]  Mockapetris, P. and RFC Publisher, "Domain names -
              concepts and facilities", STD 13, RFC 1034,
              DOI 10.17487/RFC1034, November 1987,
              <https://www.rfc-editor.org/info/rfc1034>.

   [RFC1035]  Mockapetris, P. and RFC Publisher, "Domain names -
              implementation and specification", STD 13, RFC 1035,
              DOI 10.17487/RFC1035, November 1987,
              <https://www.rfc-editor.org/info/rfc1035>.

   [RFC2046]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part Two: Media Types", RFC 2046,
              DOI 10.17487/RFC2046, November 1996,
              <https://www.rfc-editor.org/info/rfc2046>.

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

   [RFC2234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", RFC 2234, DOI 10.17487/RFC2234,
              November 1997, <https://www.rfc-editor.org/info/rfc2234>.

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   [RFC4122]  Leach, P., Mealling, M., Salz, R., and RFC Publisher, "A
              Universally Unique IDentifier (UUID) URN Namespace",
              RFC 4122, DOI 10.17487/RFC4122, July 2005,
              <https://www.rfc-editor.org/info/rfc4122>.

   [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234,
              DOI 10.17487/RFC5234, January 2008,
              <https://www.rfc-editor.org/info/rfc5234>.

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

   [RFC5870]  Mayrhofer, A. and C. Spanring, "A Uniform Resource
              Identifier for Geographic Locations ('geo' URI)",
              RFC 5870, DOI 10.17487/RFC5870, June 2010,
              <https://www.rfc-editor.org/info/rfc5870>.

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

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

   [RFC6901]  Bryan, P., Ed., Zyp, K., and M. Nottingham, Ed.,
              "JavaScript Object Notation (JSON) Pointer", RFC 6901,
              DOI 10.17487/RFC6901, April 2013,
              <https://www.rfc-editor.org/info/rfc6901>.

   [RFC7095]  Kewisch, P., "jCard: The JSON Format for vCard", RFC 7095,
              DOI 10.17487/RFC7095, January 2014,
              <https://www.rfc-editor.org/info/rfc7095>.

   [RFC7493]  Bray, T., Ed., "The I-JSON Message Format", RFC 7493,
              DOI 10.17487/RFC7493, March 2015,
              <https://www.rfc-editor.org/info/rfc7493>.

   [RFC7529]  Daboo, C. and G. Yakushev, "Non-Gregorian Recurrence Rules
              in the Internet Calendaring and Scheduling Core Object
              Specification (iCalendar)", RFC 7529,
              DOI 10.17487/RFC7529, May 2015,
              <https://www.rfc-editor.org/info/rfc7529>.

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   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/info/rfc7942>.

   [RFC8126]  Cotton, M., Leiba, B., Narten, T., and RFC Publisher,
              "Guidelines for Writing an IANA Considerations Section in
              RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8141]  Saint-Andre, P. and J. Klensin, "Uniform Resource Names
              (URNs)", RFC 8141, DOI 10.17487/RFC8141, April 2017,
              <https://www.rfc-editor.org/info/rfc8141>.

   [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259,
              DOI 10.17487/RFC8259, December 2017,
              <https://www.rfc-editor.org/info/rfc8259>.

6.2.  Informative References

   [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,
              <https://www.rfc-editor.org/info/rfc3261>.

   [RFC3339]  Klyne, G. and C. Newman, "Date and Time on the Internet:
              Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
              <https://www.rfc-editor.org/info/rfc3339>.

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

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
              <https://www.rfc-editor.org/info/rfc4648>.

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

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   [RFC6473]  Saint-Andre, P., "vCard KIND:application", RFC 6473,
              DOI 10.17487/RFC6473, December 2011,
              <https://www.rfc-editor.org/info/rfc6473>.

   [RFC6474]  Li, K. and B. Leiba, "vCard Format Extensions: Place of
              Birth, Place and Date of Death", RFC 6474,
              DOI 10.17487/RFC6474, December 2011,
              <https://www.rfc-editor.org/info/rfc6474>.

   [RFC6715]  Cauchie, D., Leiba, B., and K. Li, "vCard Format
              Extensions: Representing vCard Extensions Defined by the
              Open Mobile Alliance (OMA) Converged Address Book (CAB)
              Group", RFC 6715, DOI 10.17487/RFC6715, August 2012,
              <https://www.rfc-editor.org/info/rfc6715>.

   [RFC6869]  Salgueiro, G., Clarke, J., and P. Saint-Andre, "vCard
              KIND:device", RFC 6869, DOI 10.17487/RFC6869, February
              2013, <https://www.rfc-editor.org/info/rfc6869>.

   [RFC8174]  Leiba, B. and RFC Publisher, "Ambiguity of Uppercase vs
              Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174,
              DOI 10.17487/RFC8174, May 2017,
              <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8499]  Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS
              Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,
              January 2019, <https://www.rfc-editor.org/info/rfc8499>.

   [RFC8605]  Hollenbeck, S. and R. Carney, "vCard Format Extensions:
              ICANN Extensions for the Registration Data Access Protocol
              (RDAP)", RFC 8605, DOI 10.17487/RFC8605, May 2019,
              <https://www.rfc-editor.org/info/rfc8605>.

Authors' Addresses

   Robert Stepanek
   Fastmail
   PO Box 234, Collins St West
   Melbourne  VIC 8007
   Australia
   Email: rsto@fastmailteam.com

   Mario Loffredo
   IIT-CNR
   Via Moruzzi,1
   56124 Pisa
   Italy

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   Email: mario.loffredo@iit.cnr.it

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