/abort - Offer your opponent to abort the current game
/accept - Accept an offer (ie. a tabeback or a match challenge)
/addlist - or /+ - add an item to a list. (ie. /+notify asko would add me to your notify list)
/adjourn - if you or your opponent has lag offer an adjourn, you can finish the game later
/alias - Display or set aliases. (ie. /alias Hello shout hello all, would set the alias hello for. at your next login you could type Hello and it will make automatically the Hello all shout for you. just test it on chessnet :)
/allobservers - or short /all , will show you a list with names whom observing your game
/assess - Try /assess yourname Dumbo on chess.net and you will see a list with the possible rating changes
/assist - If you need help use /assist i need help. And an available Admin or Guide will help you.
/clearmessages - Delete old messages. (also look to /message)
/cview - Show Room parameters from a Room you are in.
/date - Show the current Server date and time.
/decline - Decline an offer. (ie. a match challenge or a takeback)
/draw - Offer a draw to your opponent