[Mailman-Users] subject line

Hello,

I am new to Mailman. I have searched thru FAQs and manuals but cannot find the answer there.

I want to block discussions about viruses and stuff like that on the list, and I'd like to do that by putting a filter on the word 'virus' in the subject line. Where should I add that filter? In the Privacy Block (Hold posts with header value matching a specified regexp.)??? And what is the syntax?

Thanks

Ary