The Yahoo! Message Boards Ignore Settings allow registered users to ignore the posts of other designated users. Each user maintains their own user Ignore List. In order to use the ignore feature, you'll need to sign in with a registered Yahoo! ID. If you don't have a Yahoo! ID, you can register now. Registration is free and easy.
When you add a user to your Ignore List, you won't see additional messages by that user in the message boards. Messages posted by ignored users are replaced by a message indicating "you are ignoring this post." The Ignore Settings gives you the ability to turn the filter on and off. You can also add or delete specific authors from your Ignore List.
Find out more about the Ignore User Filter: