/w Sends to the person after the /w (tab will cycle through)
/wf will send to a friend who is online, even if they are not in the same lobby/game (again tab cycles through them)
/a does team chat in game (assume you already know this one)
/f - Broadcasts to all online friends in your friends list (I only learned this one from one of the DT guys the other day - thanks Tyr)
