vCard Extensions for Instant Messaging (IM)

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 and RFC 2426 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) 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 "sip" indicates to use SIP/SIMPLE, "xmpp" indicates to use XMPP, "irc" indicates to use IRC, "ymsgr" indicates to use yahoo, "msn" might indicate to use Microsoft messenger, "aim" indicates to use AOL, and "im" or "pres" indicates that a CPIM or CPP gateway should be used. The normative definition of this new vCard type is given in , and an informational ABNF is provided in .

The required email to define this extension (as defined in RFC2425 ) 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 ). 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

The following ABNF grammar extends the grammar found in RFC 2425 () and RFC 2426 ().

;For name="IMPP" param = impp-param ; Only impp parameters are allowed value = URI ; URI defined in 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

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

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.

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