https://app.knowbase.one/vault/rfc/docid/3085
RFC2779: Instant Messaging / Presence Protocol Requirements
Network Working Group M. Day Request for Comments: 2779 Lotus Category: Informational S. Aggarwal Microsoft ...
https://app.knowbase.one/vault/rfc/docid/5210
RFC4770: vCard Extensions for Instant Messaging (IM)
Network Working Group C. Jennings Request for Comments: 4770 Cisco Systems Category: Standards Track J. Reschke, Ed. greenbytes ...