You can use any RLV command, really, but only the ones that are actually doing something (change a group, force something, etc.) will probably be useful. For commands that chat a response back you'll need some other device to process the response.
The commands "doing" something are listed in the "RLV command" field. If you hit the arrow down key while your cursor is in that field will show the entire list.
For a detailed description of the commands, please refer to the RLV documentation:
LSL Protocol/RestrainedLoveAPI - Second Life Wiki