on [<modes>]raw_irc [<serial#>] [-|^]<match> { <action> }

Everything an irc server sends you is routed through this hook first. This allows you to pre-filter anything from a server before it is handled by the client, in case the client doesn't know what to do with it, or you want it handled differently.

Because every on raw_irc is checked for every line from the server, every one you add makes the client a little bit slower. Be thoughtful and only use on raw_irc if there isn't another on you can use.

Danger – catching something with on raw_irc suppresses the normal handling, so be warned – you can really screw things up by intercepting important messages, and this would not be considered a bug.