I just received a book that has stray pen marks on the cover.  I assume this is a RWAP under no stains but want to make sure before I RWAP the person who sent this book.  I want to make sure I quote the right rule to them as to why I RWAP this book.  TIA.

If it's just a few pen marks I would not RWAP. 

I won't RWAP unless the ink has water damaged the book or has smeared.   (I would consider RWAP if the ink is smearing and getting on my hands.  To me, that edges over into being a stain.)  Pen marks are allowed on the edges.  They are allowed on non-text pages.  Reminder marks are allowed. 

It is a series of scribbles in a circle in the middle of the cover of the book.  Like a small child got a hold of a pen and marked up the book, or someone was writing on something circular and kept marking off the edge or tracing the edge.

I'd see if it was removable with something like Goo Gone, personally.  I've had books with names written on the outside front cover in Sharpie, and those are postable, so I don't see why a few pen marks would not be as well.  Pen marks don't usually fall into the staining category unless they are really pervasive or like Emily said, the ink has damaged the book in some way.  My interpretation of the rules is that there cannot be any writing on text pages.  Inscriptions, names, etc. on covers or non-text pages do not make it unpostable to me.

Pen marks (and marker and the like) are allowed on the cover of the book (and other places in and on the book, EXCEPT text pages).

Unless you think there are so many or they are so numerous that the book falls under the "must be in generally good condition"  exception to specific rules.

But you won't find a specific rule against writing on the cover, because there is no such rule.

Most members here interpret "stains" to generally mean any substance besides water (which also isnt allowed under water damage anyway) or writing implements of some kind (which are generally allowed except on text pages, or if there are "too many", which is, of course, open to widely varying interpretation).

My own personal feeling about it is, I would definitely post a book with pen marks on the cover, especially if that was the only "questionable" thing "wrong" with the book. I probably woudn't post a yellowing book, that also falls open to certain pages, that also has creased up covers, and also some non-text pages missing, and pen marks on the cover .... even though individually, all of those things are allowed ... but together all in the same book, I wouldn't post it. But especially if the pen is the only questionable issue with the book, yup, I would post it, too.

As the others have said, pen marks on the cover are permissable under the rules, so this would not be an RWAP.

Marked received in good condition!  Thanks