This command will send a notice to everyone in the room. It will appear as if the primary room bot has sent a notice to the room.
/as chan #chat notice This room is for fun clean chat.
Since people don't expect to see room notices as often and rarely use them, this can be a less confusing way than CHAN MESSAGE to let the bot send the occasional text to a room. But as with messages if you send too many through the bot you may confuse the people in the room.