Forum Moderators: open
Method and apparatus for retrieving documents based on information other than document content [164.195.100.11]
These techniques may be used, for example, to implement a Web search service that produces more accurate search results or that prevents certain documents, such as p*rn*gr*phic materials, from appearing in search results.
I think some times they have done a good job of enacting it, if in fact some of it comes out what they state here.
Nonetheless, it's always good to know what not to do and these patents are always good at providing those answers.