The command /join <channel name> allow you to join a player created chat channel.  You can be in up to 10 of these at once.  These channels can be seen across all servers (for instance, serverwide.thebazaar), on the server you play on (for instance, a bazaar channel for auctioning gear), or be password protected (and moderated) to protect sensitive information (such as an officer meeting for a guild).

To talk in each channel, you need to find out what channel number the channel you wish to say something in is.  To do this, type /list.  That will bring up a list of channel names along with the number of people in each channel.  Then, type in /# <text> (where # is the number of the channel you want to talk in).

To join a password protected channel, you first need to find out not only the name of the channel, but the password.  Once you have both pieces of information, type in /join <channel name>:<password>.  To join a chat channel on another server, put the name of the server in front of the channel's name (/join antonius.bazaar).

Player made chat channels are not permanent, meaning that once the last person leaves, the channel is gone, with one exception.  Password protected channels last for 24 hours after everyone leaves.

Please Note: /chat and / can be replaced with a ;, for example: /chat set can become ;set