+ u <nickname>[@<server>]
+
+ Set/unset channel message blocking for messages
+ sent by normal users. When set the server will
+ only deliver messages sent by channel founder or
+ channel operator. Client may set this mode only
+ to itself.
+
+ r <nickname>[@<server>]
+
+ Set/unset channel message blocking for messages
+ sent by robots. When set the server will not
+ deliver message from users that has been marked
+ as robots. Client may set this mode only to
+ itself.
+