vCard IM extension: vCard Extensions for Instant Messaging (IM)
Add instant messaging addresses to digital contact cards.
Jennings, C. and J. Reschke, Ed., "vCard Extensions for Instant Messaging (IM)", RFC 4770, DOI 10.17487/RFC4770, January 2007, <https://www.rfc-editor.org/info/rfc4770>.
@misc{rfc4770,
series = {Request for Comments},
number = 4770,
howpublished = {RFC 4770},
publisher = {RFC Editor},
doi = {10.17487/RFC4770},
url = {https://www.rfc-editor.org/info/rfc4770},
author = {C. Jennings and J. Reschke},
title = {{vCard Extensions for Instant Messaging (IM)}},
pagetotal = 7,
year = 2007,
month = jan,
} RFC text
Contents
Network Working Group C. Jennings
Request for Comments: 4770 Cisco Systems
Category: Standards Track 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 (C) 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:
o An indication of the type of communication for which this URI is
appropriate. This can be a value of PERSONAL or BUSINESS.
o An indication of the location of a device associated with this
URI. Values can be HOME, WORK, or MOBILE.
o 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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AI ELI5
On this page
§1Introduction
The vCard is a standard format for storing contact information, defined in RFC 2425 and RFC 2426. It holds names, phone numbers, email addresses and other details about a person in a portable format. As instant messaging (IM) and presence protocol (PP) applications became widespread, users wanted to save IM contact information in their address books alongside this other data.
RFC 4770 extends vCard with a new field type called IMPP (Instant Messaging and Presence Protocol). This allows a URI that identifies an IM or presence address to be stored in a vCard, just like email and phone numbers. A single vCard can contain multiple IMPP entries, and each entry can specify what kind of communication it is best for.
vCard is how your computer stores contact information. This adds a new type of contact information: instant messaging addresses, like a chat app username or ID.
§2The IMPP Type and Its Parameters
The IMPP type entry in a vCard contains a single URI (Uniform Resource Identifier) that points to an IM or PP service. The scheme of the URI indicates which protocol to use. Common examples include sip: for SIP/SIMPLE, xmpp: for XMPP, irc: for IRC, ymsgr: for Yahoo Messenger, msn: for Microsoft Messenger, aim: for AOL Instant Messenger, or im: and pres: for CPIM and CPP gateways.
IMPP entries can include optional TYPE parameters that describe when the address should be used. These include PERSONAL or BUSINESS to indicate the communication context, and HOME, WORK, or MOBILE to indicate the device or location. The PREF parameter marks a preferred address, similar to how it works for telephone numbers.
An IMPP entry is like an email or phone field: it has an address and optional labels saying if it is for work, home, mobile, or if it is your preferred contact method.
§3Example Usage
A simple vCard with an IMPP entry might look like this: it declares a vCard for Alice Doe and includes an IMPP entry with the URI im:alice@example.com, marked as personal and preferred. The recipient would know to use an instant messaging protocol to reach Alice at that address.
Different IM systems can be stored in separate IMPP entries within the same vCard. For example, one entry might use xmpp: for XMPP-based messaging, another sip: for SIP/SIMPLE calling, and another aim: for AOL Instant Messenger. This flexibility lets users share multiple IM contact options without duplicating their vCard structure.
You can add an IMPP field to a contact card saying 'you can reach me at alice@example.com on instant messaging', just like you would add an email address.
BEGIN:vCard
VERSION:3.0
FN:Alice Doe
IMPP;TYPE=personal,pref:im:alice@example.com
END:vCard§4IANA Registration
RFC 4770 formally registers the IMPP type with IANA as an extension to the text/directory MIME type. The registration specifies that IMPP contains a single URI, that the type parameter can include purpose and location hints, and that the intended usage is COMMON, meaning it is expected to be widely used in vCard implementations.
The registration was requested through the IETF MIME Direct mailing list in October 2004 and documents the type name, purpose, encoding, allowed parameters and special notes for implementers.
The Internet organization IANA officially added IMPP to the list of valid vCard field types so that all contact card systems would recognize and support it.
§5Security and Privacy
RFC 4770 does not introduce new security issues beyond those present in the vCard specification itself. However, the RFC notes an important consideration: many people regard their presence and instant messaging information as more sensitive than their phone numbers or email addresses. Revealing when someone is online or available can expose personal information about their habits and schedule.
Any system that stores, exchanges, or transfers vCards needs to carefully manage the privacy of IM contact information and protect it with the same care given to other personal data.
Knowing if someone is online right now tells you a lot about when they are free. So IM contact information needs to be kept private and secure, just like passwords.