The silence command allows you to ignore a specific user. For example, if a user is flooding or harassing you, the user can be silenced. When you silence a user, all messages, notices or ctcp events initiated by that user will no longer reach you. Others see this user's messages normally. To use the silence command, specify /silence plus a user@host mask or nickname. Any user that matches that mask will not be able to send private messages or notices to you. To remove a silence, issue the same command with a minus sign "-" in front of the hostmask or nick
Example:
/silence rowdy
/silence Flooder!trill@pm02.digex.net
/silence *!*@*.digex.net
/silence -Rowdy!*@*.digex.net
This is a good command to stop people from annoying you. You will see anything they say in rooms you have in common, so you won't miss anything important. Yet you won't see any private messages. Silencing people is a very good tactic that is not used as often as it should be. There may be many immature people who get on your nerves, simply not dealing with them is best. Then you can enjoy chatting in peace with the people who do interest you.