This is the desired action you would like to take with listings flagged as dead links by the Link Management Assistant. The default setting is to generate a report showing you which listings it's determined to be dead. You can then review each listing to determine whether or not it is in fact active. The alternative is to trust the URL validation feature and have the Link Management Assistant delete all such listings automatically. However, understand that even though the validation process is as accurate as possible, it's not entirely fool proof, so you use this feature with that knowledge in mind.