Load plugin mod_topic, and it will provide 3 new user commands:
!topic - set new topic
!cleartopic - reset the topic (use default hub description)
!showtopic - show the current topic
Dynamic commands are user commands that can be added dynamically to
the hub by a plugin.
The example plugin (mod_example.c) adds a !example command that when
invoked send a message to the user who invoked it.
Jan Vidar Krey