:::A name is what something or someone is known as.  That's the whole point of naming things.  The goal is to allow users to most easily find information, hence the reliance on common names.  Mark Twain's "real name" was Samuel Langhorne Clemens, but we don't put his article under that title because it would be rather difficult to find from a search engine.  Similarly with Bill Clinton ("real name":William Jefferson Clinton) and Julius Caesar ("real name":Gaius Iulius Gaii Filius Gaii Nepos Caesar).  "William Marcy Tweed" gets only 815 hits on google, while "Boss Tweed" gets 28,000, more than 34X as many.  If by "real name" you mean the most formal name is the only allowed form, then clearly there is no meaing to a concept of a "common" name.  Please see Wikipedia:Naming conventions (common names) for a full explanation.