I decided to do the search for you:
http://www.gnutellaforums.com/showth...threadid=32192 That applies to Mac OSX for keyword filters. For Windows you'll need to go to your LW menu Tools>Options>Filters>Keyword to find it.
Here's another link that may help you:
http://www.gnutellaforums.com/showth...highlight=spam
And another with helpful points:
http://www.gnutellaforums.com/showth...threadid=32034