http://wiki.spiralknights.com/Release_Notes_2011-04-19
Added /trade channel in Haven. Please use this channel for all trade related chat.
Added commands to join and leave channels: /join zone, /leave trade
/join 2 or /join trade = join trade chat channel
/leave 1 or /leave zone = leave general chat channel
/leave 2 or /leave trade = leave trade chat channel