When the Blue Coat WebFilter (BCWF) service analyzes a sub-domain, (subdomain1.example.org) it typically assigns the same category as the top-level domain, (example.org). However, if the subdomain has significantly unique content, it will be rated differently than the top-level domain.
BCWF uses a method called Rating Types
to determine how to classify a URLS and their subsequent directories. Whenever it assigns a rating to the URL, the BCWF service considers four rating elements:
- File: A single page rating that applies to a single file, where the contents and details of that file are different than those of the root domain.
- Directory: Rates a single URL path. This rating type only covers the specific directory where it was applied, and is not often used. For example, while example.org is rated, example.org/dir1/ might appear as unrated.
- Cascaded Directory: Rates multiple directories under a domain as different categories. As BCWF scans the directories on a given domain, it assigns categories to the content as appropriate. To use a real-world example, www.reddit.com is rated as Newsgroups/Forums, www.redd.com/r/funny is rated as Humor/Jokes. Pretty much every directory under that domain represents a different category; some of which are typically blocked by most web filter policies.
- Trusted Domain: If contents in all subfolders match the content category on the domain as a whole, the entire site can be classified with the same category using the Trusted Domain rating type.