Yeah, I had issues with my books being "claimed" by the wrong owner, even people who walked in with nothing in his hands, and everyone else saw it.
So I always write in my name, and I add in errata that actually address's rules issues, not cosmetic's, and I'll tab books, etc.. to help make it easier for to use and find things. Even my books which are signed by author/creators. These books are mine, they are not leaving my possession until I die, so I will use them however I wish.
But only in books for which I actually run games. Otherwise they only get my name put in them and left in otherwise pristine shape on my shelves until that day I actually get to run it comes along.