The Concise Oxford Dictionary, 7th Edition

New (N): Brand New Book

Excellent (EX): The book has no torn or missing pages, has no writing or highlighting. It's like new.

Very Good (VG): The book has no torn, missing pages, writing or highlighting. Might have some creases on the spine; no hard cracks; maybe slight forward lean and short inscription inside; perhaps very minor bumping on the corners of the book.

Good (G): This book has no large tears or any missing pages, but it may contain very little writing or highlighting. A few creases on the spine, perhaps a forward lean, bumping on corners or shelf wear; maybe an inscription inside or some shelf wear or a small tear or two on the dustjacket.

Acceptable (AC): This book has no missing pages and may have considerable writing or highlighting but the text must not be obscured.