vCard Extensions for IMPP

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 RFC 2119.

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 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, though a parameter should occur at most once in a given IMPP entry. The type of URI indicates what protocols might be useable for accessing it, but this document does not define any of the types. For example a URI type of "sip" might indicate to use SIP/SIMPLE, "xmpp" indicates to use jabber, "irc" indicates to use IRC, "ymsgr" indicates to use yahoo, "msn" might indicate to use messenger, "aim" indicates to use AOL, and "im" or "pres" indicates to use a CPIM or CPP gateway. The normative definition of this new vCard type is given in , and an informational ABNF is provided in .

To: ietf-mime-directory@imc.org Subject: Registration of text/directory MIME type IMPP Type name: IMPP Type purpose: To specify the URI for instant messaging and presence protocol communication 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 can include the type parameter "TYPE" to specify an intended use for the URI. The TYPE parameter values can include: 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. An indication of some of the core capabilities of this instant messaging system. Values can be PRES, VIDEO, VOICE, TEXT, SMS, NUMERIC, and BEEP. PRES indicates the system supports some presence protocol. VIDEO, VOICE, and TEXT indicate the system supports voice, video, and text messaging respectively. SMS indicates short text messages are supported. Short is not defined here, but something like 160 octets may be a reasonable assumption. NUMERIC indicates that only numeric text messages are allowed. BEEP indicates that the only information the system can deliver is that a message was sent to the target user. The value STORE indicates that the system can store messages for future delivery to the intended user. The value PREF indicates this is a preferred address and has the same semantics as the PREF value in a TEL type.

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 impp-param = "TYPE" "=" impp-type *("," impp-type) impp-type = "PERSONAL" / "BUSINESS" / ; purpose of communications "HOME" / "WORK" / "MOBILE" / ; useful? "VIDEO" / "VOICE" / "TEXT" / ; core capabilities "SMS" / "NUMERIC" / "BEEP" / "PRES" ; needed??? "STORE" / ; like MSG "PREF" / iana-token / x-name; ; Values are case insensitive

BEGIN:vCard VERSION:3.0 FN:John Doe IMPP;TYPE=personal,text,store,pref:im:john@example.com END:vCard

Are PERSONAL and BUSINESS a conflict in meaning with HOME and WORK? In the TEL type HOME and WORK indicated a location, but they have slowly come to be indicators that personal or business communication is requested. Would a person with both a personal mobile phone and a work mobile phone have HOME,MOBILE and WORK,MOBILE? Is there any need for SMS, NUMERIC, BEEP? This is not a system for negotiating capabilities and these seem like too fine detail. On the other hand the existing vCard supports pagers and such, and these definitions would help users avoid sending large messages to GSM cell phones. Is STORE needed? It mirrors the functionality of MSG in the TEL type and is a feature supported by many IM systems.

forms the IANA registration.

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