xCard: vCard XML Representation

Internet Engineering Task Force (IETF)                      S. Perreault
Request for Comments: 6351                                      Viagenie
Category: Standards Track                                    August 2011
ISSN: 2070-1721


                    xCard: vCard XML Representation

Abstract

   This document defines the XML schema of the vCard data format.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6351.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  2
   2.  Conventions  . . . . . . . . . . . . . . . . . . . . . . . . .  2
   3.  The Schema . . . . . . . . . . . . . . . . . . . . . . . . . .  2
   4.  Example: Author's XML vCard  . . . . . . . . . . . . . . . . .  3
   5.  Design Considerations  . . . . . . . . . . . . . . . . . . . .  4
     5.1.  Extensibility  . . . . . . . . . . . . . . . . . . . . . .  6
     5.2.  Limitations  . . . . . . . . . . . . . . . . . . . . . . .  7
   6.  Format Conversions . . . . . . . . . . . . . . . . . . . . . .  8
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 10
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 11
     8.1.  Registration of the XML Namespace  . . . . . . . . . . . . 11
     8.2.  Media Type . . . . . . . . . . . . . . . . . . . . . . . . 11
   9.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 12
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 12
     10.2. Informative References . . . . . . . . . . . . . . . . . . 13
   Appendix A.  Relax NG Schema . . . . . . . . . . . . . . . . . . . 14

1.  Introduction

   vCard [RFC6350] is a data format for representing and exchanging
   information about individuals and other entities.  It is a text-based
   format (as opposed to a binary format).  This document defines xCard,
   an XML [W3C.REC-xml-20081126] representation for vCard.  The
   underlying data structure is exactly the same, enabling a 1-to-1
   mapping between the original vCard format and the XML representation.
   The XML formatting may be preferred in some contexts where an XML
   engine is readily available and may be reused instead of writing a
   standalone vCard parser.

   Earlier work on an XML format for vCard was started in 1998 by Frank
   Dawson [VCARD-DTD].  Sadly, it did not take over the world.

2.  Conventions

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

3.  The Schema

   The schema is expressed in the RELAX NG language [ISO.19757-2.2008]
   and is found in Appendix A.

4.  Example: Author's XML vCard

   <?xml version="1.0" encoding="UTF-8"?>
   <vcards xmlns="urn:ietf:params:xml:ns:vcard-4.0">
     <vcard>
       <fn><text>Simon Perreault</text></fn>
       <n>
         <surname>Perreault</surname>
         <given>Simon</given>
         <additional/>
         <prefix/>
         <suffix>ing. jr</suffix>
         <suffix>M.Sc.</suffix>
       </n>
       <bday><date>--0203</date></bday>
       <anniversary>
         <date-time>20090808T1430-0500</date-time>
       </anniversary>
       <gender><sex>M</sex></gender>
       <lang>
         <parameters><pref><integer>1</integer></pref></parameters>
         <language-tag>fr</language-tag>
       </lang>
       <lang>
         <parameters><pref><integer>2</integer></pref></parameters>
         <language-tag>en</language-tag>
       </lang>
       <org>
         <parameters><type><text>work</text></type></parameters>
         <text>Viagenie</text>
       </org>
       <adr>
         <parameters>
           <type><text>work</text></type>
           <label><text>Simon Perreault
   2875 boul. Laurier, suite D2-630
   Quebec, QC, Canada
   G1V 2M2</text></label>
         </parameters>
         <pobox/>
         <ext/>
         <street>2875 boul. Laurier, suite D2-630</street>
         <locality>Quebec</locality>
         <region>QC</region>
         <code>G1V 2M2</code>
         <country>Canada</country>
       </adr>
       <tel>
         <parameters>
           <type>
             <text>work</text>
             <text>voice</text>
           </type>
         </parameters>
         <uri>tel:+1-418-656-9254;ext=102</uri>
       </tel>
       <tel>
         <parameters>
           <type>
             <text>work</text>
             <text>text</text>
             <text>voice</text>
             <text>cell</text>
             <text>video</text>
           </type>
         </parameters>
         <uri>tel:+1-418-262-6501</uri>
       </tel>
       <email>
         <parameters><type><text>work</text></type></parameters>
         <text>simon.perreault@viagenie.ca</text>
       </email>
       <geo>
         <parameters><type><text>work</text></type></parameters>
         <uri>geo:46.766336,-71.28955</uri>
       </geo>
       <key>
         <parameters><type><text>work</text></type></parameters>
         <uri>http://www.viagenie.ca/simon.perreault/simon.asc</uri>
       </key>
       <tz><text>America/Montreal</text></tz>
       <url>
         <parameters><type><text>home</text></type></parameters>
         <uri>http://nomis80.org</uri>
       </url>
     </vcard>
   </vcards>

5.  Design Considerations

   The general idea is to map vCard parameters, properties, and value
   types to XML elements.  For example, the "FN" property is mapped to
   the "fn" element.  In turn, that element contains a text element
   whose content corresponds to the vCard property's value.

   vCard parameters are also mapped to XML elements.  They are contained
   in the <parameters> element, which is contained in property elements.
   For example, the "TYPE" parameter applied to the "TEL" property would
   look like the following in XML:

     <tel>
       <parameters>
         <type>
           <text>voice</text>
           <text>video</text>
         </type>
       </parameters>
       <uri>tel:+1-555-555-555</uri>
     </tel>

   Parameters taking a list of values are simply repeated multiple
   times, once for each value in the list.

   Properties having structured values (e.g., the "N" property) are
   expressed by XML element trees.  Element names in that tree (e.g.,
   "surname", "given", etc.) do not have a vCard equivalent since they
   are identified by position in plain vCard.

   Line folding is a non-issue in XML.  Therefore, the mapping from
   vCard to XML is done after the unfolding procedure is carried out.
   Conversely, the mapping from XML to vCard is done before the folding
   procedure is carried out.

   A top-level <vcards> element is used as root.  It contains one or
   more <vcard> elements, each representing a complete vCard.  The
   <vcards> element MUST be present even when only a single vCard is
   present in an XML document.

   The group construct (Section 3.2 in [RFC6350]) is represented with
   the <group> element.  The "name" attribute contains the group's name.
   For example:

     <vcards>
       <vcard>
         <group name="contact">
           <fn>...</fn>
           <email>...</email>
         </group>
         <group name="media">
           <photo>...</photo>
         </group>
         <categories>...</categories>
       </vcard>
     </vcards>

   is equivalent to:

     BEGIN:VCARD
     VERSION:4.0
     contact.FN=...
     contact.EMAIL=...
     media.PHOTO=...
     CATEGORIES=...
     END:VCARD

5.1.  Extensibility

   The original vCard format is extensible.  New properties, parameters,
   data types and values (collectively known as vCard elements, not to
   be confused with XML elements) can be registered with IANA (see
   [RFC6350], Section 10.2).  It is expected that these vCard extensions
   will also specify extensions to the XML format described in this
   document.

   New XML vCard property and parameter element names MUST be lower-
   case.  This is necessary to ensure that round-tripping between XML
   and plain-text vCard works correctly.

   Unregistered extensions (i.e., those starting with "X-" and
   "VND-...-") are expressed in XML by using elements starting with "x-"
   and "vnd-...-".  Usage of XML namespaces [W3C.REC-xml-names-20091208]
   for extensibility is RECOMMENDED for extensions that have no
   equivalent in plain-text vCard.  Refer to Section 6 for the
   implications when converting between plain-text vCard and XML.

   Examples:

     <x-my-prop>
       <parameters>
         <pref><integer>1</integer></pref>
       </parameters>
       <text>value goes here</text>
     </x-my-prop>

     <ext:my-prop
         ext:xmlns="http://example.com/extensions/my-vcard">
       <parameters>
         <pref><integer>1</integer></pref>
       </parameters>                 <!-- Core vCard elements  -->
       <text>value goes here</text>  <!-- are still accessible -->
     </ext:my-prop>

   Note that extension elements do not need the "X-" or "VND-" prefix in
   XML.  The XML namespace mechanism is sufficient.

   A vCard XML parser MUST ignore XML elements and attributes for which
   it doesn't recognize the expanded name.  The normal behavior of
   ignoring XML processing instructions whose target is not recognized
   MUST also be followed.

   In the original vCard format, the "VERSION" property was mandatory
   and played a role in extensibility.  In XML, this property is absent.
   Its role is played by the vCard core namespace identifier, which
   includes the version number. vCard revisions will use a different
   namespace.

   Parameters containing a list of values are expressed using a list of
   elements in XML (e.g., the <type> element).

5.2.  Limitations

   The schema does not validate the cardinality of properties.  This is
   a limitation of the schema definition language.  Cardinalities of the
   original vCard format [RFC6350] MUST still be respected.

   Some constructs (e.g., value enumerations in type parameters) have
   additional ordering constraints in XML.  This is a result of
   limitations of the schema definition language, and the order is
   arbitrary.  The order MUST be respected in XML for the vCard to be
   valid.  However, reordering as part of conversion to or from plain
   vCard MAY happen.

6.  Format Conversions

   When new properties or "X-" properties are used, a vCard<->xCard
   converter might not recognize them or know what the appropriate
   default value types are, yet they need to be able to preserve the
   values.  A similar issue arises for unrecognized property parameters.
   As a result, the following rules are applied when dealing with
   unrecognized properties and property parameters:

   o  When converting from vCard to xCard:

      *  Any property that does not include a "VALUE" parameter and
         whose default value type is not known MUST be converted using
         the value type XML element <unknown>.  The content of that
         element is the unprocessed value text.

      *  Any unrecognized property parameter MUST be converted using the
         value type XML element <unknown>, with its content set to the
         parameter value text, treated as if it were a text value, or
         list of text values.

      *  The content of "XML" properties is copied as is to XML.

      *  Property and parameter XML element names are converted to
         lower-case.

      *  Property value escaping is undone.  For example, "\n" becomes a
         NEWLINE character (ASCII decimal 10).

      *  Double-quoting of parameter values, as well as backslash
         escaping in parameter values, is undone.  For example,
         PARAM="\"foo\",\"bar\"" becomes <param>"foo","bar"</param>.

   o  When converting xCard to vCard:

      *  Properties in the vCard 4 namespace:

         +  If the converter knows of a specific plain-text
            representation for this property, it uses it.  For example,
            the <adr> element corresponds to the "ADR" property, which
            is encoded using comma-separated lists separated by
            semicolons.

         +  Otherwise, the property name is taken from the element name,
            property parameters are taken from the <parameters> element,
            and the content of the property is taken from the content of
            the value element.  If the property element has attributes
            or contains other XML elements, they are dropped.

         +  If a standard property's XML element contains XML elements
            and attributes for which the converter doesn't recognize the
            expanded name, they are dropped.  Therefore, it is
            RECOMMENDED to limit extensions to the property level to
            ensure that all data is preserved intact in round-trip
            conversions.

      *  Properties in other namespaces are wrapped as is inside an
         "XML" property.

      *  Any <unknown> property value XML elements are converted
         directly into vCard values.  The containing property MUST NOT
         have a "VALUE" parameter.

      *  Any <unknown> parameter value XML elements are converted as if
         they were <text> value type XML elements.

      *  Property and parameter names are converted to upper-case.

      *  Property value escaping (Section 3.3 of [RFC6350]) is carried
         out.  For example, a NEWLINE character (ASCII decimal 10)
         becomes "\n".

      *  Double-quoting of parameter values, as well as backslash
         escaping in parameter values, is carried out.  For example,
         <param>"foo","bar"</param> becomes PARAM="\"foo\",\"bar\"".

   For example, these two vCards are equivalent:

     <?xml version="1.0"?>
     <vcards xmlns="urn:ietf:params:xml:ns:vcard-4.0">
       <vcard>
         <fn><text>J. Doe</text></fn>
         <n>
           <surname>Doe</surname>
           <given>J.</given>
           <additional/>
           <prefix/>
           <suffix/>
         </n>
         <x-file>
           <parameters>
             <mediatype><text>image/jpeg</text></mediatype>
           </parameters>
           <unknown>alien.jpg</unknown>
         </x-file>
         <a xmlns="http://www.w3.org/1999/xhtml"
            href="http://www.example.com">My web page!</a>
       </vcard>
     </vcards>


     BEGIN:VCARD
     VERSION:4.0
     FN:J. Doe
     N:Doe;J.;;
     X-FILE;MEDIATYPE=image/jpeg:alien.jpg
     XML:<a xmlns="http://www.w3.org/1999/xhtml"\n
         href="http://www.example.com">My web page!</a>
     END:VCARD

7.  Security Considerations

   All the security considerations applicable to plain vCard [RFC6350]
   are applicable to this document as well.

   XML Signature [W3C.CR-xmldsig-core1-20110303] and XML Encryption
   [W3C.CR-xmlenc-core1-20110303] can be used with xCard to provide
   authentication and confidentiality.

8.  IANA Considerations

8.1.  Registration of the XML Namespace

   URI:  urn:ietf:params:xml:ns:vcard-4.0

   Registrant Contact:  The IESG <iesg@ietf.org>

   XML:  None.  Namespace URIs do not represent an XML specification.

8.2.  Media Type

   This section defines the MIME media type [RFC4288] for use with
   vCard-in-XML data.

   To:  ietf-types@iana.org

   Subject:  Registration of media type application/vcard+xml

   Type name:  application

   Subtype name:  vcard+xml

   Required parameters:  none

   Optional parameters:  charset as defined for application/xml in
      [RFC3023]; per [RFC3023], use of the charset parameter with the
      value "utf-8" is "STRONGLY RECOMMENDED".

   Encoding considerations:  Same as encoding considerations of
      application/xml as specified in [RFC3023].

   Security considerations:  This media type has all of the security
      considerations described in [RFC3023], plus those listed in
      Section 7.

   Interoperability considerations:  This media type provides an
      alternative syntax to vCard data [RFC6350] based on XML.

   Published specification:  This specification.

   Applications that use this media type:  Applications that currently
      make use of the text/vcard media type can use this as an
      alternative.  In general, applications that maintain or process
      contact information can use this media type.

   Additional information:

      Magic number(s):  none

      File extension(s):  XML data should use ".xml" as the file
         extension.

      Macintosh file type code(s):  none

   Person & email address to contact for further information:  Simon
      Perreault <simon.perreault@viagenie.ca>

   Intended usage:  COMMON

   Restrictions on usage:  none

   Author:  Simon Perreault

   Change controller:  IETF

9.  Acknowledgments

   Thanks to the following people for their input:

   Alexey Melnikov, Barry Leiba, Bjorn Hoehrmann, Cyrus Daboo, Joe
   Hildebrand, Joseph Smarr, Marc Blanchet, Mike Douglass, Peter Saint-
   Andre, Robins George, Zahhar Kirillov, Zoltan Ordogh.


10.  References

10.1.  Normative References

   [ISO.19757-2.2008]
              International Organization for Standardization,
              "Information technology -- Document Schema Definition
              Language (DSDL) -- Part 2: Regular-grammar-based
              validation -- RELAX NG", ISO International
              Standard 19757-2, October 2008.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3023]  Murata, M., St. Laurent, S., and D. Kohn, "XML Media
              Types", RFC 3023, January 2001.

   [RFC6350]  Perreault, S., "vCard Format Specification", RFC 6350,
              August 2011.

   [W3C.REC-xml-20081126]
              Paoli, J., Yergeau, F., Maler, E., Bray, T., and C.
              Sperberg-McQueen, "Extensible Markup Language (XML) 1.0
              (Fifth Edition)", World Wide Web Consortium
              Recommendation REC-xml-20081126, November 2008,
              <http://www.w3.org/TR/2008/REC-xml-20081126>.

   [W3C.REC-xml-names-20091208]
              Bray, T., Hollander, D., Layman, A., Tobin, R., and H.
              Thompson, "Namespaces in XML 1.0 (Third Edition)", World
              Wide Web Consortium Recommendation REC-xml-names-20091208,
              December 2009,
              <http://www.w3.org/TR/2009/REC-xml-names-20091208>.

10.2.  Informative References

   [RFC4288]  Freed, N. and J. Klensin, "Media Type Specifications and
              Registration Procedures", BCP 13, RFC 4288, December 2005.

   [VCARD-DTD]
              Dawson, F., "The vCard v3.0 XML DTD", Work in Progress,
              June 1998.

   [W3C.CR-xmldsig-core1-20110303]
              Roessler, T., Solo, D., Yiu, K., Reagle, J., Hirsch, F.,
              Eastlake, D., and M. Nystroem, "XML Signature Syntax and
              Processing Version 1.1", World Wide Web Consortium CR CR-
              xmldsig-core1-20110303, March 2011,
              <http://www.w3.org/TR/2011/CR-xmldsig-core1-20110303>.

   [W3C.CR-xmlenc-core1-20110303]
              Eastlake, D., Reagle, J., Roessler, T., and F. Hirsch,
              "XML Encryption Syntax and Processing Version 1.1", World
              Wide Web Consortium CR CR-xmlenc-core1-20110303,
              March 2011,
              <http://www.w3.org/TR/2011/CR-xmlenc-core1-20110303>.

Appendix A.  Relax NG Schema

default namespace = "urn:ietf:params:xml:ns:vcard-4.0"

### Section 3.3: vCard Format Specification
#
# 3.3
iana-token = xsd:string { pattern = "[a-zA-Z0-9-]+" }
x-name = xsd:string { pattern = "x-[a-zA-Z0-9-]+" }

### Section 4: Value types
#
# 4.1
value-text = element text { text }
value-text-list = value-text+

# 4.2
value-uri = element uri { xsd:anyURI }

# 4.3.1
value-date = element date {
    xsd:string { pattern = "\d{8}|\d{4}-\d\d|--\d\d(\d\d)?|---\d\d" }
  }

# 4.3.2
value-time = element time {
    xsd:string { pattern = "(\d\d(\d\d(\d\d)?)?|-\d\d(\d\d?)|--\d\d)"
                         ~ "(Z|[+\-]\d\d(\d\d)?)?" }
  }

# 4.3.3
value-date-time = element date-time {
    xsd:string { pattern = "(\d{8}|--\d{4}|---\d\d)T\d\d(\d\d(\d\d)?)?"
                         ~ "(Z|[+\-]\d\d(\d\d)?)?" }
  }

# 4.3.4
value-date-and-or-time = value-date | value-date-time | value-time

# 4.3.5
value-timestamp = element timestamp {
    xsd:string { pattern = "\d{8}T\d{6}(Z|[+\-]\d\d(\d\d)?)?" }
  }

# 4.4
value-boolean = element boolean { xsd:boolean }

# 4.5
value-integer = element integer { xsd:integer }

# 4.6
value-float = element float { xsd:float }

# 4.7
value-utc-offset = element utc-offset {
    xsd:string { pattern = "[+\-]\d\d(\d\d)?" }
  }

# 4.8
value-language-tag = element language-tag {
    xsd:string { pattern = "([a-z]{2,3}((-[a-z]{3}){0,3})?|[a-z]{4,8})"
                         ~ "(-[a-z]{4})?(-([a-z]{2}|\d{3}))?"
                         ~ "(-([0-9a-z]{5,8}|\d[0-9a-z]{3}))*"
                         ~ "(-[0-9a-wyz](-[0-9a-z]{2,8})+)*"
                         ~ "(-x(-[0-9a-z]{1,8})+)?|x(-[0-9a-z]{1,8})+|"
                         ~ "[a-z]{1,3}(-[0-9a-z]{2,8}){1,2}" }
  }

### Section 5: Parameters
#
# 5.1
param-language = element language { value-language-tag }?

# 5.2
param-pref = element pref {
    element integer {
      xsd:integer { minInclusive = "1" maxInclusive = "100" }
    }
  }?

# 5.4
param-altid = element altid { value-text }?

# 5.5
param-pid = element pid {
    element text { xsd:string { pattern = "\d+(\.\d+)?" } }+
  }?

# 5.6
param-type = element type { element text { "work" | "home" }+ }?

# 5.7
param-mediatype = element mediatype { value-text }?

# 5.8
param-calscale = element calscale { element text { "gregorian" } }?

# 5.9
param-sort-as = element sort-as { value-text+ }?

# 5.10
param-geo = element geo { value-uri }?

# 5.11
param-tz = element tz { value-text | value-uri }?

### Section 6: Properties
#
# 6.1.3
property-source = element source {
    element parameters { param-altid, param-pid, param-pref,
                         param-mediatype },
    value-uri
  }

# 6.1.4
property-kind = element kind {
    element text { "individual" | "group" | "org" | "location" |
                   x-name | iana-token }*
  }

# 6.2.1
property-fn = element fn {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type }?,
    value-text
  }

# 6.2.2
property-n = element n {
    element parameters { param-language, param-sort-as, param-altid }?,
    element surname { text }+,
    element given { text }+,
    element additional { text }+,
    element prefix { text }+,
    element suffix { text }+
  }

# 6.2.3
property-nickname = element nickname {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type }?,
    value-text-list
  }

# 6.2.4
property-photo = element photo {
    element parameters { param-altid, param-pid, param-pref, param-type,
                         param-mediatype }?,
    value-uri
  }

# 6.2.5
property-bday = element bday {
    element parameters { param-altid, param-calscale }?,
    (value-date-and-or-time | value-text)
  }

# 6.2.6
property-anniversary = element anniversary {
    element parameters { param-altid, param-calscale }?,
    (value-date-and-or-time | value-text)
  }

# 6.2.7
property-gender = element gender {
    element sex { "" | "M" | "F" | "O" | "N" | "U" },
    element identity { text }?
  }

# 6.3.1
param-label = element label { value-text }?
property-adr = element adr {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type, param-geo, param-tz,
                         param-label }?,
    element pobox { text }+,
    element ext { text }+,
    element street { text }+,
    element locality { text }+,
    element region { text }+,
    element code { text }+,
    element country { text }+
  }

# 6.4.1
property-tel = element tel {
    element parameters {
      param-altid,
      param-pid,
      param-pref,
      element type {
        element text { "work" | "home" | "text" | "voice"
                     | "fax" | "cell" | "video" | "pager"
                     | "textphone" }+
      }?,
      param-mediatype
    }?,
    (value-text | value-uri)
  }

# 6.4.2
property-email = element email {
    element parameters { param-altid, param-pid, param-pref,
                         param-type }?,
    value-text
  }

# 6.4.3
property-impp = element impp {
    element parameters { param-altid, param-pid, param-pref,
                         param-type, param-mediatype }?,
    value-uri
  }

# 6.4.4
property-lang = element lang {
    element parameters { param-altid, param-pid, param-pref,
                         param-type }?,
    value-language-tag
  }

# 6.5.1
property-tz = element tz {
    element parameters { param-altid, param-pid, param-pref,
                         param-type, param-mediatype }?,
    (value-text | value-uri | value-utc-offset)
  }

# 6.5.2
property-geo = element geo {
    element parameters { param-altid, param-pid, param-pref,
                         param-type, param-mediatype }?,
    value-uri
  }

# 6.6.1
property-title = element title {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type }?,
    value-text
  }

# 6.6.2
property-role = element role {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type }?,
    value-text
  }

# 6.6.3
property-logo = element logo {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type, param-mediatype }?,
    value-uri
  }

# 6.6.4
property-org = element org {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type, param-sort-as }?,
    value-text-list
  }

# 6.6.5
property-member = element member {
    element parameters { param-altid, param-pid, param-pref,
                         param-mediatype }?,
    value-uri
  }

# 6.6.6
property-related = element related {
    element parameters {
      param-altid,
      param-pid,
      param-pref,
      element type {
        element text {
          "work" | "home" | "contact" | "acquaintance" |
          "friend" | "met" | "co-worker" | "colleague" | "co-resident" |
          "neighbor" | "child" | "parent" | "sibling" | "spouse" |
          "kin" | "muse" | "crush" | "date" | "sweetheart" | "me" |
          "agent" | "emergency"
        }+
      }?,
      param-mediatype
    }?,
    (value-uri | value-text)
  }

# 6.7.1
property-categories = element categories {
    element parameters { param-altid, param-pid, param-pref,
                         param-type }?,
    value-text-list
  }

# 6.7.2
property-note = element note {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type }?,
    value-text
  }

# 6.7.3
property-prodid = element prodid { value-text }

# 6.7.4
property-rev = element rev { value-timestamp }

# 6.7.5
property-sound = element sound {
    element parameters { param-language, param-altid, param-pid,
                         param-pref, param-type, param-mediatype }?,
    value-uri
  }

# 6.7.6
property-uid = element uid { value-uri }

# 6.7.7
property-clientpidmap = element clientpidmap {
    element sourceid { xsd:positiveInteger },
    value-uri
  }

# 6.7.8
property-url = element url {
    element parameters { param-altid, param-pid, param-pref,
                         param-type, param-mediatype }?,
    value-uri
  }

# 6.8.1
property-key = element key {
    element parameters { param-altid, param-pid, param-pref,
                         param-type, param-mediatype }?,
    (value-uri | value-text)
  }

# 6.9.1
property-fburl = element fburl {
    element parameters { param-altid, param-pid, param-pref,
                         param-type, param-mediatype }?,
    value-uri
  }

# 6.9.2
property-caladruri = element caladruri {
    element parameters { param-altid, param-pid, param-pref,
                         param-type, param-mediatype }?,
    value-uri
  }

# 6.9.3
property-caluri = element caluri {
    element parameters { param-altid, param-pid, param-pref,
                         param-type, param-mediatype }?,
    value-uri
  }

# Top-level grammar
property = property-adr | property-anniversary | property-bday
         | property-caladruri | property-caluri | property-categories
         | property-clientpidmap | property-email | property-fburl
         | property-fn | property-geo | property-impp | property-key
         | property-kind | property-lang | property-logo
         | property-member | property-n | property-nickname
         | property-note | property-org | property-photo
         | property-prodid | property-related | property-rev
         | property-role | property-gender | property-sound
         | property-source | property-tel | property-title
         | property-tz | property-uid | property-url
start = element vcards {
    element vcard {
      (property
       | element group {
           attribute name { text },
           property*
         })+
    }+
  }

Author's Address

   Simon Perreault
   Viagenie
   2600 boul. Laurier, Suite 625
   Quebec, QC  G1V 4W1
   Canada

   Phone: +1 418 656 9254
   EMail: simon.perreault@viagenie.ca
   URI:   http://www.viagenie.ca