I have a book that was requested. It meets all the guidelines, but I do have one question about the conditions that isn't mentioned in the guidelines.

The book is fine - no tears, no rips, no water damage - you're standard postable book. But the cover (which is completely intact) is what I am questioning. Its a paperback. The cover is solid black with the title and author's name in dark blue. I guess from all the handling of numerous readers, the dark blue writing is barely visible.

I hesitate to PM the requestor because then you run into the issue of what if they don't respond before you mail it, etc.

It seems postable to me. When I received it, I did not mark it RWAP. 

Anyone have an opinion on it?

I would say it's postable and just natural aging of the book. It sounds like it was probably not easy to read the writing in the first place.  Probably intentionally.

Is that the actual cover the book was published with?  It almost sounds like a proof or ARC.