_Added in 1.5_

*/mode #channel|nickname [[+|-]modechars [parameters]]*

Use to control a channel, there are many modes depending on server, some common ones are:

+b <nick!ident@host> - Ban a mask from the channel
-b <nick!ident@host> - Unban a mask from the channel
+i - Make channel invite only (everyone needs to be invited through /invite to enter the channel)
-i - Disable invite only
+l <N> - Set a user limit on the channel, when user count reaches N, no new users will be allowed
-l - Disable user limit
+m - Make channel moderated, only users with voice/channel operators can speak
-m - Disable channel moderation
+n - External messages from users not in the channel is not allowed
-n - External messages from users not in the channel is allowed
+o <nick> - Make a user channel operator
-o <nick> - Demote a channel operator
+p - Set channel as private
-p - Set channel as public
+s - Set channel as secret (will no be shown in channel /list and so on)
-s - Set channel as not secret
+t - Only channel operators can change topic
-t - Everyone can change topic
+k <key> = Set a secret key for the channel, only users who knows the key can enter
-k - Remove the secret key, everyone can enter