USER MODE q

Usage: UMODE +|-q
Usage: MODE <nick> +|-q
q - Quiet
This mode will disable a users ability to talk on the server at all. Once set it can't be unset. Normally this is used in an event client class where you set the initial mode to +q so that the user can't speak on the server.
Privilege: user
Examples:
/mode jimmers +q
/umode +q