The classification I'm looking for has nothing to do with the origin of the name. It should describe where the name is (and was) used. Multiple categories can be assigned to a single name. Atticus could be described as Ancient Roman, Literature, and (maybe) English. But where else is it (significantly) used? I don't assign categories until I'm relatively sure they're complete.
You can see the available categories at http://www.behindthename.com/usage.html
. You can read the descriptions at the top of the individual pages.
Please email me with any results!