/afk: This will set the player as "away from keyboard" or "no longer away from keyboard" depending on current status.
/cs: This will bring up the Support (information, feedback and bug report) interface.
/dnd: This will set you to "Do Not Disturb" status or "No longer DND" depending on your current status.
/friend: <player character's name>: This will add a player's character to your friends list.
/ignore: <player character's name>: This will set a player's character to be ignored.
/leave: <channel number>: This will allow you to leave a chat channel when you add the number of the channel to the command.
/played: This will show you how much time was spent on your character.
/time: This will show the current time based on the user's computer clock, as well as the server's current time.
/help: This will display all other commands available to you and your character.