This article is from the Internet Personals: Advice for Gay Men FAQ, by Fred Young email@example.com and Dean Esmay firstname.lastname@example.org with numerous contributions by others.
This really just applies to Usenet, not the Web. It is a feature
in some news reading software to filter out unwanted messages. You
tell it not to show you articles containing certain words or
phrases or posted by certain people. It can be helpful in some
places, but until more people start using simple, easily
identifiable titles to their personal ads, this will remain a
mostly-useless feature for personal ad readers.