It joins everyone that has the addon on the same server into a chat channel so you can talk with people.
If higher levels are there you can type "p2p?" and it will reply with a yes if they can inv automatically.
From there you can pst them "inv" and they auto inv.
hijacking this thread, is there a reason why f2paddon is limited to the same realm? is it a blizzard imposed limitation for addons? or some other reason?
Yea you can't talk cross realm like that. You can pst battletags but in the chat outside of the game, not in game (as far as I remember). Maybe something could be made around that but that would be a complete rework from Yasueh, who's retired.