I have a book where the previous owner stamped their name and address on the front page of the book, then placed a plain white sticker over it to try and cover up the name/address.  The book is otherwise postable.  The sticker doesn't obscure any of the original text of the book.  Looks like name plates, library stickers and BookCrossing stickers are okay, but I didn't find this particular thing in the rules.   Is this postable, or does the sticker over the stamped name make it unpostable? 

From what I can tell, this should fall under the same rules as the library stickers, book crossing, book plate rules.  In my opinion the book would be perfectly postable, especially since no text is effected.

Yes, it's postable.  Names inside books are fine, and the person just put the sticker over it for privacy reasons (I'm assuming) rather than black it out with a marker or something.  He/she probably thought the sticker looked neater/cleaner than a marker marking up the inside of the book.  Since it doesn't affect the text, it's allowed, just as names and other stickers would be.

I agree -- postable.

Postable!