I'm showing my ignorance, but where is the flyleaf located on a book?  Would this be the inside cover? I have a book I want to post, but it has a short inscription to me, on the inside cover and I'm not sure if it meets the "guidelines" or not.

any help would be appreciated :)

The flyleaf is the blank page that is in the front of the book, not the inside cover.  You can post your book with the inscription on the inside cover.  That is the same idea as an inscription on the flyleaf.  No problem. 

thanks for your help!! Would it be ok to blacken the inscription out with a marker, when posting?   I have a few "donated" books I rec'd from my school, when we were cleaning out our bookroom, that had a name in them, too.

I would find the black marker more offensive than the inscription. No rule either way, just stating, that to me, the inscription is something that is in lots of books, black blotches of marker would be strikingly ugly.

I'd leave the inscription and not use a marker to blacken it out.

I agree; I wouldn't like to see a black marker ruin the page. It's ugly!  Since it's postable, leave it be.

I'd leave the inscription.  It's allowed and it's nicer to look at then black marks.  IMHO