You know how some books have a "preview page" at the very beginning, before the title page, with a particularly exciting scene from the book? I have a book where that page has been ripped out; all the other pages are intact. Is this postable? The page isn't a part of the story - it's just meant to get the reader interested enough to buy the book - but it is a "text page" in that there was text on it.

I would say that the book is postable, some may say otherwise....I had an occassion one time where a library pocket obscured information on the author and TPTB said...."Well, text pages are meant to be =  pages containing the story."