l <limit> Set/unset channel's user limit
a <passphrase> Set/unset passphrase for channel that must
be provided when joining to the channel.
- b <username!nickname@server>
- Add client to/remove client from ban list
- I <username!nickname@server>
- Add client to/remove client from invite list
- c <cipher>
- Set/unset channel's cipher
+ c <cipher> Set/unset channel's cipher
Multiple modes can be set/unset at once if the modes does not
require any arguments. If mode requires an argument then only