/avatar xx - To change your Player's symbols enter this command and replace xx with your symbols.
/store - To add current Custom Map to your map list. So you could load it quickly next time.
/handicap 500 - To add lag (ping) to yourself and reduce it to other players. For example: if you are afk and don't want to be kicked. (replace 500 with 'delay in miliseconds')
/clear_password - To delete room password so everybody could come. You have to be an admin of the room.
/colors < Team > < Angle > < AvatarColor > [ Color1 ] [ Color2 ] [ Color3 ] - To change colors of player's circles. More about it: HaxColors.com.
/colors < Team > clear - To remove team colors. You have to be an admin of the room.
P button - To pause game during match. You have to be an admin of the room.