Syntax: DEVOICE [#channel [nick]]
Devoices a selected nick on a channel. If nick is not given, it will devoice you. If channel and nick are not given, it will devoice you on all channels you're on, provided you have the rights to.
By default, limited to AOPs or those with level 5 access  and above on the channel, or to VOPs or those with level 3  and above for self devoicing.