Blacklist URL Patterns are a quick and easy way to block hundreds of URLs which are similiar in content from appearing in your comments/trackbacks. You simply supply the word or word combinations that may appear in URLs you would want to block.
This page is for entering a raw regular expression to block unwanted content in user submissions. Your entry will be evaluated as is, except that it defaults to case insensitive. If you know regular expressions, that shouldn't cause you much problem. As always, be careful. Regular expressions are like chainsaws. You can clear a forest or cut off your own arm.