Network Working Group
Request for Comments: 4770
Category: Standards Track
C. Jennings
Cisco Systems
J. Reschke, Ed.
greenbytes
January 2007

vCard Extensions for Instant Messaging (IM)

Status of This Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright © The IETF Trust (2007).

Abstract

This document describes an extension to vCard to support Instant Messaging (IM) and Presence Protocol (PP) applications. IM and PP are becoming increasingly common ways of communicating, and users want to save this contact information in their address books. It allows a URI that is associated with IM or PP to be specified inside a vCard.

Table of Contents

   1. Overview ........................................................2
   2. IANA Considerations .............................................3
   3. Formal Grammar ..................................................4
   4. Example .........................................................4
   5. Security Considerations .........................................4
   6. Acknowledgments .................................................4
   7. References ......................................................5
   
      7.1. Normative References .......................................5
      7.2. Informational References ...................................5

1. Overview

As more and more people use various instant messaging (IM) and presence protocol (PP) applications, it becomes important for them to be able to share this contact address information, along with the rest of their contact information. RFC 2425 [1] and RFC 2426 [2] define a standard format for this information, which is referred to as vCard. This document defines a new type in a vCard for representing instant IM and PP URIs. It is very similar to existing types for representing email address and telephone contact information.

The type entry to hold this new contact information is an IMPP type. The IMPP entry has a single URI (see RFC 3986 [3]) that indicates the address of a service that provides IM, PP, or both. Also defined are some parameters that give hints as to when certain URIs would be appropriate. A given vCard can have multiple IMPP entries, but each entry can contain only one URI. Each IMPP entry can contain multiple parameters. Any combination of parameters is valid, although a parameter should occur, at most, once in a given IMPP entry.

The type of URI indicates what protocols might be usable for accessing it, but this document does not define any of the types. For example, a URI type of

o "sip" [5] indicates to use SIP/SIMPLE,
o "xmpp" [6] indicates to use XMPP,
o "irc" indicates to use IRC,
o "ymsgr" indicates to use yahoo,
o "msn" might indicate to use Microsoft messenger,
o "aim" indicates to use AOL, and
o "im" [7] or "pres" [8] indicates that a CPIM or CPP gateway should

be used.

The normative definition of this new vCard type is given in Section 2, and an informational ABNF is provided in Section 3.

2. IANA Considerations

   The required email to define this extension (as defined in RFC 2425
   [1]) was sent on October 29, 2004, to the ietf-mime-direct@imc.org
   mailing list with the subject "Registration of text/directory MIME
   type IMPP" (see <http://www.imc.org/ietf-mime-direct/mail-
   archive/msg00068.html>).
   
   This specification updates the "text/directory MIME Types"
   subregistry in the "text/directory MIME Registrations" registry at
   http://www.iana.org/assignments/text-directory-registrations with the
   following information:
   
   Type name: IMPP

Type purpose: To specify the URI for instant messaging and presence protocol communications with the object the vCard represents.

   Type encoding: 8bit

Type value: A single URI. The type of the URI indicates the protocol that can be used for this contact.

Type special notes: The type may include the type parameter "TYPE" to specify an intended use for the URI. The TYPE parameter values include one or more of the following:

  • An indication of the type of communication for which this URI is appropriate. This can be a value of PERSONAL or BUSINESS.
  • An indication of the location of a device associated with this URI. Values can be HOME, WORK, or MOBILE.
  • The value PREF indicates this is a preferred address and has the same semantics as the PREF value in a TEL type.

Additional information can be found in RFC 4770.

   Intended usage: COMMON

3. Formal Grammar

The following ABNF grammar [4] extends the grammar found in RFC 2425 [1] (Section 5.8.2) and RFC 2426 [2] (Section 4).

;For name="IMPP"

    param      = impp-param ; Only impp parameters are allowed
    
    value      = URI
                 ; URI defined in Section 3 of [3]
    
    impp-param = "TYPE" "=" impp-type *("," impp-type)
    
    impp-type  = "PERSONAL" / "BUSINESS" / ; purpose of communications
                 "HOME" / "WORK" / "MOBILE" /
                 "PREF" /
                 iana-token / x-name;
                 ; Values are case insensitive

4. Example

   BEGIN:vCard
   VERSION:3.0
   FN:Alice Doe
   IMPP;TYPE=personal,pref:im:alice@example.com
   END:vCard

5. Security Considerations

This does not introduce additional security issues beyond the current vCard specification. It is worth noting that many people consider their presence information more sensitive than other address information. Any system that stores or transfers vCards needs to carefully consider the privacy issues around this information.

6. Acknowledgments

Thanks to Brian Carpenter, Lars Eggert, Ted Hardie, Paul Hoffman, Sam Roberts, and Pekka Pessi for their comments.

7. References

7.1. Normative References

   [1]  Howes, T., Smith, M., and F. Dawson, "A MIME Content-Type for
   
        Directory Information", RFC 2425, September 1998.
   
   [2]  Dawson, F. and T. Howes, "vCard MIME Directory Profile", RFC
        2426, September 1998.
   
   [3]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
        Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986,
        January 2005.
   
   [4]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
        Specifications: ABNF", RFC 4234, October 2005.

7.2. Informational References

   [5]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
        Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP:
        Session Initiation Protocol", RFC 3261, June 2002.
   
   [6]  Saint-Andre, P., "Internationalized Resource Identifiers (IRIs)
        and Uniform Resource Identifiers (URIs) for the Extensible
        Messaging and Presence Protocol (XMPP)", RFC 4622, July 2006.
   
   [7]  Peterson, J., "Common Profile for Instant Messaging (CPIM)", RFC
        3860, August 2004.
   
   [8]  Peterson, J., "Common Profile for Presence (CPP)", RFC 3859,
        August 2004.

Authors' Addresses

   Cullen Jennings
   Cisco Systems
   170 West Tasman Drive
   MS: SJC-21/2
   San Jose, CA  95134
   USA
   
   Phone: +1 408 902-3341
   EMail: fluffy@cisco.com
   
   Julian F. Reschke (editor)
   greenbytes GmbH
   Hafenweg 16
   Muenster, NW  48155
   Germany
   
   Phone: +49 251 2807760
   EMail: julian.reschke@greenbytes.de

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