Ask LISnews: Racy book covers and WebPAC content ratings?

Our library system\’s new web catalog contains images of some book covers, and some of those images might be a little racy: Sexual State of the Union, Drawing the Female Nude, and so on. I\’m wondering what sort of content rating is appropriate for the catalog as a whole (it does \’contain\’ visual depictions of partial and full nudity, after all). I\’d also be interested in finding examples of books with cover images that might offend patrons? Sometimes there\’s an offensive cover on an otherwise unobjectionable item, such as Blind Faith\’s album showing a nude teenage girl holding a remarkably phallic model airplane. So a more general (and, yes, titillating) question is: what books have the raciest cover images?