Network Working Group                                       S. Perreault
Internet-Draft                                                  Viagenie
Intended status: Standards Track                           March 8,                             May 9, 2010
Expires: September 9, November 10, 2010

                        vCard XML Representation
                    draft-ietf-vcarddav-vcardxml-02
                    draft-ietf-vcarddav-vcardxml-03

Abstract

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

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  The Schema . . . . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  Example: Author's XML vCard  . . . . . . . . . . . . . . . . .  3
   4.  Design Considerations  . . . . . . . . . . . . . . . . . . . .  5
     4.1.  Extensibility  . . . . . . . . . . . . . . . . . . . . . .  5
     4.2.  Limitations  . . . . . . . . . . . . . . . . . . . . . . .  6
   5.  Security Considerations  Format Conversions . . . . . . . . . . . . . . . . . . . . . .  7
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . .  8
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  7
     6.1.  8
     7.1.  Registration of the XML Namespace  . . . . . . . . . . . .  7
   7.  9
   8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .  7
   8.  9
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . .  7
     8.1.  9
     9.1.  Normative References . . . . . . . . . . . . . . . . . . .  7
     8.2.  9
     9.2.  Informative References . . . . . . . . . . . . . . . . . .  7  9
   Appendix A.  Relax NG Schema . . . . . . . . . . . . . . . . . . .  7  9
   Appendix B.  Change Log (to be removed by RFC Editor prior to
                publication)  . . . . . . . . . . . . . . . . . . . . 13 15
     B.1.  Changes in -02 -03 . . . . . . . . . . . . . . . . . . . . . . 13 15
     B.2.  Changes in -01 -02 . . . . . . . . . . . . . . . . . . . . . . 14 15
     B.3.  Changes in -01 . . . . . . . . . . . . . . . . . . . . . . 16
     B.4.  Changes in -00 . . . . . . . . . . . . . . . . . . . . . . 14 16

1.  Introduction

   vCard [I-D.ietf-vcarddav-vcardrev] is a data format for representing
   and exchanging information about individuals.  It is a text-based
   format (as opposed to a binary format).  This document defines an XML
   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 stand-alone vCard parser.

   Earlier work on an XML format for vCard was started in 1998 by Frank
   Dawson [I-D.dawson-vcard-xml-dtd].  Sadly it did not take over the
   world.

2.  The Schema

   The schema is expressed in the RELAX NG language
   [relaxng][relaxng-compact] and is found in Appendix A.

3.  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><text>Perreault</text></surname>
         <given><text>Simon</text></given>
         <prefix><text/></prefix>
         <prefix/>
         <suffix>
           <text>ing. jr.</text>
           <text>M.Sc.</text>
         </suffix>
       </n>
       <bday><date>--0203</date></bday>
       <anniversary>
         <date-time>20090808T1430-0500</date-time>
       </anniversary>
       <sex>1</sex>
       <sex><integer>1</integer></sex>
       <lang>
         <parameters><pref>1</pref></parameters>
         <language-tag>fr</language-tag>
       </lang>
       <lang>
         <parameters><pref>2</pref></parameters>
         <language-tag>en</language-tag>
       </lang>
       <org>
         <parameters><type>work</type></parameters>
         <text>Viagenie</text>
       </org>
       <adr>
         <parameters><type>work</type></parameters>
         <pobox><text/></pobox>
         <pobox/>
         <ext><text>Suite 625</text></ext>
         <street><text>2600 boul. Laurier</text></street>
         <locality><text>Quebec</text></locality>
         <region><text>QC</text></region>
         <code><text>G1V 4W1</text></code>
         <country><text>Canada</text></country>
       </adr>
       <tel>
         <parameters>
           <type>work</type>
           <type>voice</type>
         </parameters>
         <uri>tel:+1-418-656-9254;ext=102</uri>
       </tel>
       <tel>
         <parameters>
           <type>work</type>
           <type>text</type>
           <type>voice</type>
           <type>cell</type>
           <type>video</type>
         </parameters>
         <uri>tel:+1-418-262-6501</uri>
       </tel>
       <tel>
         <parameters>
           <type>work</type>
           <type>fax</type>
         </parameters>
         <uri>tel:+1-418-656-9257</uri>
       </tel>
       <email>
         <parameters><type>work</type></parameters>
         <text>simon.perreault@viagenie.ca</text>
       </email>
       <geo>
         <parameters><type>work</type></parameters>
         <uri>geo:46.772673,-71.282945</uri>
       </geo>
       <key>
         <parameters><type><work/></type></parameters>
         <parameters><type>work</type></parameters>
         <uri>http://www.viagenie.ca/simon.perreault/simon.asc</uri>
       </key>
       <tz><text>America/Montreal</text></tz>
       <class>PUBLIC</class>
       <class><text>PUBLIC</text></class>
     </vcard>
   </vcards>

4.  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.  That element in turn 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>voice</type>
         <type>video</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.

4.1.  Extensibility

   The original vCard format is extensible.  New properties, parameters,
   data types and values (collectively known as vCard objects) can be
   registered from IANA.  It is expected that these vCard extensions
   will also specify extensions to the XML format described in this
   document.  This is not a requirement: a separate document may be used
   instead.

   Unregistered extensions (i.e. those starting with "X-" and
   "VND-...-") can be expressed in XML by making use of XML namespaces.
   They simply correspond to elements outside of the core namespace.
   For example:

     <ext:my-prop
         ext:xmlns="http://example.com/extensions/my-vcard">
       <parameters>
         <pref>1</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 behaviour 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).

4.2.  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 [I-D.ietf-vcarddav-vcardrev] 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.

5.  Format Conversions

   When converting from XML vCard (this specification) to plain-text
   vCard [I-D.ietf-vcarddav-vcardrev], the following rules apply:

   o  Properties in the vCard 4 namespace:

   o

      *  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 semi-colons.

      *  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.

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

   When converting from plain-text vCard [I-D.ietf-vcarddav-vcardrev] to
   XML vCard (this specification), the following rules apply:

   o  The content of "XML" properties is converted as-is to XML.

   o  Properties for which the converter knows of a specific XML
      representation use it.  For example, the "ADR" property is
      represented using the <adr> element and related sub-elements.

   o  Other properties are converted to XML in the following way:

   o

      *  The XML namespace of the property element is set to the vCard 4
         namespace.

      *  The name of the property element is set to that of the
         property.

      *  If the property has attributes, they get translated as-is into
         sub-elements of the <parameters> element

      *  The property element contains a single <text> element whose
         content is copied as-is from the property's value.

   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><text>Doe</text></surname>
             <given><text>J.</text></given>
             <prefix/>
             <suffix/>
           </n>
           <x-file>
             <parameters><type>image/jpeg</type></parameters>
             <text>alien.jpg</text>
           </x-file>
           <a xmlns="http://www.w3.org/1999/xhtml"
              href="http://www.example.com">My web page!</a>
         </vcard>
       </vcards>
     </xml>

     BEGIN:VCARD
     VERSION:4.0
     FN:J. Doe
     N:Doe;J.;;
     X-FILE;TYPE=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

6.  Security Considerations

   All the security considerations applicable to plain vCard
   [I-D.ietf-vcarddav-vcardrev] are applicable to this document as well.

6.

7.  IANA Considerations

6.1.
7.1.  Registration of the XML Namespace

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

   Registrant Contact:  Simon Perreault <simon.perreault@viagenie.ca>

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

7.

8.  Acknowledgements

   Thanks to the following people for their input:

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

8.

9.  References

8.1.

9.1.  Normative References

   [I-D.ietf-vcarddav-vcardrev]  Perreault, S. and P. Resnick, "vCard
                                 Format Specification",
                                 draft-ietf-vcarddav-vcardrev-09
                                 draft-ietf-vcarddav-vcardrev-11 (work
                                 in progress), October 2009. May 2010.

   [relaxng]                     Clark, J., "RELAX NG Specification",
                                 December 2001.

   [relaxng-compact]             Clark, J., "RELAX NG Compact Syntax",
                                 November 2002, <http://www.relaxng.org/
                                 compact-20021121.html>.

8.2.

9.2.  Informative References

   [I-D.dawson-vcard-xml-dtd]    Dawson, F., "The vCard v3.0 XML DTD",
                                 draft-dawson-vcard-xml-dtd-03 (work in
                                 progress), June 1998.

Appendix A.  Relax NG Schema

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

# Value types
value-text = element text { text }
value-text-list = value-text+
value-uri = element uri { xsd:anyURI }
value-date = element date {
    xsd:string { pattern = "\d{8}|\d{4}-\d\d|--\d\d(\d\d)?|---\d\d" }

  }
value-time = element time {
    xsd:string { pattern = "(\d\d(\d\d(\d\d)?)?|-\d\d(\d\d?)|--\d\d)"
                         ~ "(Z|[+\-]\d\d(\d\d)?)?" }
  }
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)?)?" }
  }
value-date-and-or-time = value-date | value-date-time | value-time
value-timestamp = element timestamp {
    xsd:string { pattern = "\d{8}T\d{6}(Z|[+\-]\d\d(\d\d)?)?" }
  }
value-boolean = element boolean { xsd:boolean }
value-integer = element integer { xsd:integer }
value-float = element float { xsd:float }
value-binary = element binary { xsd:base64Binary }
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}" }
  }

# Parameters
param-language = element language { value-language-tag }?
param-pref = element pref {
    xsd:integer { minInclusive = "1" maxInclusive = "100" }
  }?
param-pid = element pid {
    xsd:string { pattern = "\d+(\.\d+)?" }
  }?
param-type = element type { "work" | "home" }*
param-calscale = element calscale { "gregorian" }?

# Properties
property-source = element source {
    element parameters { param-pid, param-pref },
    value-uri
  }
property-name = element name { value-text }
property-kind = element kind {
    element text { "individual" | "group" | "org" |
                   "location" | "thing" }*
  }
property-fn = element fn {
    element parameters { param-language, param-pid,
                         param-pref, param-type }?,
    value-text
  }
property-n = element n {
    element parameters { param-language }?,
    element surname { value-text-list value-text-list? },
    element given { value-text-list value-text-list? },
    element prefix { value-text-list value-text-list? },
    element suffix { value-text-list value-text-list? }
  }
property-nickname = element nickname {
    element parameters { param-language, param-pid,
                         param-pref, param-type }?,
    value-text-list
  }
property-photo = element photo {
    element parameters {
      param-pid,
      param-pref,
      param-type,
      element type { element media { value-text } }?
    }?,
    (value-binary | value-uri)
  }
property-bday = element bday {
    element parameters { param-calscale }?,
    (value-date-and-or-time | value-text)
  }
property-dday = element dday {
    element parameters { param-calscale }?,
    (value-date-and-or-time | value-text)
  }
property-birth = element birth {
    element parameters { param-language }?,
    value-text
  }
property-death = element death {
    element parameters { param-language }?,
    value-text
  }
property-anniversary = element anniversary {
    element parameters { param-calscale }?,
    (value-date-and-or-time | value-text)
  }
property-sex = element sex {
    element integer { "0" | "1" | "2" | "9" }
  }

property-adr = element adr {
    element parameters {
      param-language,
      param-pid,
      param-pref,
      param-type,
      element geo { value-uri }?,
      element tz { value-text | value-uri }?
    }?,
    element pobox { value-text-list value-text-list? },
    element ext { value-text-list value-text-list? },
    element street { value-text-list value-text-list? },
    element locality { value-text-list value-text-list? },
    element region { value-text-list value-text-list? },
    element code { value-text-list value-text-list? },
    element country { value-text-list value-text-list? }
  }
property-label = element label {
    element parameters { param-language, param-pid,
                         param-pref, param-type }?,
    value-text
  }
property-tel = element tel {
    element parameters {
      param-pid,
      param-pref,
      element type { "work" | "home" | "text" | "voice"
                   | "fax" | "cell" | "video" | "pager" }*
    },
    value-uri
  }
property-email = element email {
    element parameters { param-pid, param-pref, param-type }?,
    value-text
  }
property-impp = element impp {
    element parameters { param-pid, param-pref, param-type }?,
    value-uri
  }
property-lang = element lang {
    element parameters { param-pid, param-pref, param-type }?,
    value-language-tag
  }
property-tz = element tz {
    element parameters { param-pid, param-pref, param-type }?,
    (value-text | value-uri)
  }
property-geo = element geo {
    element parameters { param-pid, param-pref, param-type }?,
    value-uri
  }
property-title = element title {
    element parameters { param-language, param-pid,
                         param-pref, param-type }?,
    value-text
  }
property-role = element role {
    element parameters { param-language, param-pid,
                         param-pref, param-type }?,
    value-text
  }
property-logo = element logo {
    element parameters {
      param-language,
      param-pid,
      param-pref,
      param-type,
      element type { element media { value-text } }?
    }?,
    (value-binary | value-uri)
  }
property-org = element org {
    element parameters { param-language, param-pid,
                         param-pref, param-type }?,
    value-text-list
  }
property-member = element member { param-pid, param-pref, value-uri }
property-related = element related {
    element parameters {
      param-pid,
      param-pref,
      element type { "work" | "home" | "parent" | "child"
        | "sibling" | "spouse" | "family" | "friend"
        | "supervisor" | "supervisee" | "assistant"
        | "colleague" | "agent" | "emergency" }*
    }?,
    (value-uri | value-text)
  }
property-categories = element categories {
    element parameters { param-pid, param-pref, param-type }?,
    value-text
  }
property-note = element note {
    element parameters { param-language, param-pid,
                         param-pref, param-type }?,
    value-text

  }
property-prodid = element prodid { value-text }
property-rev = element rev { value-timestamp }
property-sort-string = element sort-string {
    element surname { value-text }+,
    element given { value-text }*
  }
property-sound = element sound {
    element parameters {
      param-language,
      param-pid,
      param-pref,
      element type {
        element work { empty }?,
        element home { empty }?, "work" | "home" |
        element media { value-text }? } }*
      }
    }?,
    (value-binary | value-uri)
  }
property-uid = element uid { value-uri }
property-clientpidmap = element clientpidmap {
    element sourceid { xsd:positiveInteger },
    value-uri
  }
property-url = element url {
    element parameters { param-pid, param-pref, param-type }?,
    value-uri
  }
property-class = element class {
    element text { "PUBLIC" | "PRIVATE" | "CONFIDENTIAL" }
  }
property-key = element key {
    element parameters {
      param-pid,
      param-pref,
      element type {
        element work { empty }?,
        element home { empty }?, "work" | "home" |
        element media { value-text }? } }*
      }
    }?,
    (value-binary | value-uri)
  }
property-fburl = element fburl {
    element parameters { param-pid, param-pref, param-type }?,
    value-uri
  }
property-caladruri = element caladruri {
    element parameters { param-pid, param-pref, param-type }?,
    value-uri
  }

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

# Top-level grammar
property = property-adr | property-anniversary | property-bday
         | property-birth | property-caladruri | property-caluri
         | property-categories | property-class | property-clientpidmap
         | property-dday | property-death | property-email
         | property-fburl | property-fn | property-geo | property-impp
         | property-key | property-kind | property-label | property-lang
         | property-logo | property-member | property-n | property-name
         | property-nickname | property-note | property-org
         | property-photo | property-prodid | property-related
         | property-rev | property-role | property-sex
         | property-sort-string | 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*
         })+
    }+
  }

Appendix B.  Change Log (to be removed by RFC Editor prior to
             publication)

B.1.  Changes in -03

   o  Created "Format Conversions" section.

   o  Turned more <type> parameter values into plain text.

   o  Removed need for empty value elements in components.

   o  Wrapped value of <sex>, <class>, and <kind> in value elements.

B.2.  Changes in -02

   o  Synchronized with draft-ietf-vcarddav-vcardrev-10.

   o  Turned <type> parameter values into plain text.

   o  Moved the "XML" property to vCard base.

   o  Changed title to avoid confusion with XML Schema.

   o  Added prefixes "value-", "param-", and "property-" in schema.

   o  Better language for specifying what a parser must ignore.

B.2.

B.3.  Changes in -01

   o  Synchronized with draft-ietf-vcarddav-vcardrev-09.

   o  Added the <vcards> element to allow multiple vCards in a single
      XML file.

   o  Created the <parameters> container element.

   o  Use text value for enumeration in <class> element.

   o  Created the "XML" vCard property.

   o  Added IANA considerations section.

   o  Added security considerations section.

B.3.

B.4.  Changes in -00

   o  Same as draft-perreault-vcarddav-vcardxml-02.

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