- When a client tries to subscribe to another user via a presence message,
an iq message of type set holding the new roster entry reflecting this needs
to be sent back to the client.
- Messages comming from the client in the jabber:iq:roster namespace can
have an undocumented value in its subscription attribute of "remove" which
indicates they should be removed from the users roster.
These may be undocumented in the "Protocol-standard" document, but they're covered in the "jabber:iq:roster" section of the Jabber Protocol Overview, and also in my Jabber Client Developer's Cheat Sheet.
It's definitely a problem that none of the documentation is comprehensive. I had to develop my own client (and write my cheat-sheet) by having printouts of both the JPO and JPG open in front of me and constantly flipping back and forth between them. (And to get conferencing working, I had to go to the protocol-draft document for that, since the stuff in both of the previously mentioned documents is out of date.)
--Jens
