I posted some books today and just realized the two of them have a writing on the inside cover.  They were both Christmas presents and say "merry christmas 2009 Love mom and dad"  otherwise they are in like new condition.  Are they allowed to be posted? One is on someones wish list so  I am sure it will be requested soon.  Do I just PM them and let them know or should I just un-list the book? Sorry, I am new and still learning a little.

Writing on the inside cover is okay.  Writing on the text pages is not, unless it's an autographed copy of the book.  The author's signature would be okay on a text page.

It all depends on what is considered a text page (which is a gray area in the rules).

IMO, story pages are text pages, and anything written by the author (and / or editor, etc) that is intended to be read as part of the book.

Other pages (title page, copyright page, book ad pages in back, review pages in front or back, etc.) are not really text pages. It is very common for those pages to perhaps have someone's name on them, or the author's autograph, or a libary stamp or barcode, or a used bookstore stamp, etc.

I believe these are all OK and postable, as long as they are not on the text pages.

Names and writing inside book covers is postable Alyson, and welcome to PBS!