Synopsis:
   j <channel>

Description:
   J lets you join a new channel.  If you are on multiple channels,
   the specified channel will become the current one.  If you do not
   specify a channel (or channels) to join, your client will display
   your current channels, along with their respective modes and users,
   and which server you are on the channel from.

Examples:
   To join channel blah (or create it if it does not exist):
      /j blah

Aliases:
   J is identical in operation to JOIN.