User blog comment:Raylan13/Elder Scrolls Online Community Q&A/@comment-3076045-20140321065915/@comment-3076045-20140324133927

I'm not talking about just the Lusty Argonian Maid - they have actually explained that one in-game. (It was an oral tradition for a long time, I think).

I'm talking about ones like the Great Harbinger's book, which says it is written by a 3rd Century Author. (There are quite a lot of other examples, too).