Google GTalk clients (web, android, windows) have great ability to suck conversation history from server, even though conversations were done an another jabber client.
- What jabber (XMPP) functionality (XEP) is used for that or is it some custom thing?
- Why no other XMPP client (non Google) has this ability?
P.S. It is programming question, because I am asking about specific XMPP functionality.