Adina Levin writes in to say that the opposite of exonym—which I asked about earlier—is "endonym". Dictionary.com doesn't seem to have this word on file, but a little research confirms that geographers use the term unproblematically, which is good enough for me. It also appears that the "real map" is now called "Endonym Map", and drops the "real" if not from the URL, then at least the image itself.