Webfilter (licensed) vs Application Control

Historically, at least, IPS and App Control were applied before Web Filter profiles, since they are both flow-based.

So a good example would have a been a case where an administrator applied an App Control sensor to block Facebook, but also blocked the Social Networking category in a web filter. The app would be blocked, but the user would not see a replacement message (which would have been generated in the case of a proxy-based WF profile).

Exempting a site in a WF profile in this case would not affect IPS or App Control, since they would have already been checked.