+ b <nickname>[@<server>]
+
+ Set/unset channel message blocking. Client
+ may set this mode only to itself. When set
+ the server will not send channel message to
+ to the client. This mode can be used to block
+ unwanted messages if desired.
+
+ 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.
+
+ q <nickname>[@<server>]
+
+ Set/unset user as quiet. When set the user cannot
+ talk on the channel, and cannot send messages to
+ the channel. This can be used by channel operator
+ to quiet a certain misbehaving user. The user cannot
+ unset this mode itself. This mode cannot be set
+ or unset to yourself.
+
+