Are you sure that it's an snotice? Many of those are CTCP events or else actions. From your example, I don't think it's an action, but perhaps it's a CTCP?
i really have no clue. i went to the help channel and asked how i could disable all those notices (since i have already UNCHECKED all the notices, invites, CTCP, etc. in my mIRC options to NOT show in the active window and it didn't work either) and someone gave me the above code (which doesn't work also).
how would i go about to changing it to ctcp? just simply replace snotice with ctcp (btw, i've also tried just notice and NOT snotice and it doesn't work)?