From Elendor
Syntax: +COM/HAVEN
This command toggles +com/haven on and off. When you toggle +com/haven on, you
immediately leave all your channels. This is useful when you want to get
away from all the channel spam fast to do something like roleplay without
interruption. When you hit +com/haven again, you will rejoin all the
channels that you left.
Information for users of the +comset system: +Com/haven is actually a shortcut
syntax for the +COMSET system. The +com/haven command defines a channel
set on you named "HAVEN" consisting of all the channels that you are
joined to. It then +COMSET's you to a null channel set consisting of no
channels. When you toggle +com/haven off again, it +COMSET's you to the
"HAVEN" channel set and deletes it from your set of channels.