The chat commands are a part of the phpFreeChat script, not jPFChat per se. We didn't write phpFreeChat, we wrote the Joomla interface for it to work in Joomla.
Please visit: http://www.phpfreechat.net/commands?s=help for a full listing of available commands from the chat window. You can also just type /help into the chat prompt, and you'll get a listing of all the available commands.