In the ACNS 5.2.3 software and later releases, you can configure a Content Engine to bypass URL filtering for certain HTTP and HTTPS requests. This feature is supported for local list URL filtering (good and bad site lists), as well as Websense, SmartFilter, or N2H2 URL filtering.
For example, if you enable local URL filtering on the Content Engine and enable the bad sites deny feature (for example, the badfile.txt file contains the URLs that should be blocked), and the rule no-url-filtering action is a hit (a match), the Content Engine bypasses the URL filtering for that particular request; otherwise, it proceeds with URL filtering and blocks the URL request.