+ +J - Prevent autorejoin on kick. Users will not be able to
+ rejoin immediately after being kicked.
+ +K - No repeat messages. Messages that are the same as the
+ last message sent to the channel will be blocked.
+ * +M - Immune. Opers cannot be kicked from the channel. May
+ be set by admins regardless of channel status. Users
+ will not see this mode at all. Can only be set by admins.
+ ?* +O - Oper only channel. Only opers will be able to join.
+ ?* +A - Admin only channel. Only admins will be able to join.
+ Can only be set by admins.
+ ? +S - SSL only channel. Only clients connected via SSL may join.