I get a lot of my cookbooks on the used market from thift stores, library sales and yard sales.  Some of these show wear and some may have a food stain or two on favored recipe pages.  Are these postable?

This is from the Help Center under Book Conditions

• Exception: Cookbooks may have some mild staining, since these are used in the kitchen and while cooking, and some minor degree of staining could be expected in a used cookbook.  Also a small amount of writing in cookbooks could be expected

• HOWEVER, if you post a cookbook and it is stained and/or written-in, the condition must be described to the requestor in a Personal Message

• AND the described condition MUST BE AGREED TO in a reply PM before the book is sent
• This is the one of the ONLY three cases in which a PM exchange about a book is required before the book can be sent (the others are for travel guidebooks and textbooks/workbooks--see above).

this exception applies to the covers of cookbooks also.

Page edges: remainder marks are OK.  A name written on the page edges is okay (if it does not bleed in and obscure text on the text pages)