The following information concerns the specific book criteria of the various conditions of overall use.
New: The book is unused and in perfect condition.
Like New: Appears to be in perfect condition. There are no signs of major wear on the item, e.g., no markings or tear on the front or back cover, and no writing or highlighting of any kind inside the book.
Very Good: The book is unmarked and undamaged, but there are some minimal, limited signs of shelf wear.
Good: The book shows wear from consistent use, and it may contain some markings, writing or highlighting (less than 50% of the book). The book may show other signs of previous use.
Ex-Library: An ex-library book is a book that once belonged to a public library or institution and has been deemed no longer useful. An ex-library book will carry some sort of marking indicating the name of library that previously owned it. It could be a stamp, or a barcode label, or an 'old school' pocket for the checkout card. It will also probably carry some sort of stamp bearing the word 'discarded' or 'withdrawn', or the barcode has been obscured with a pen. Aside from the obvious library markings, an ex-library book will still be categorized under any of the aforementioned conditions of use.
Ex-Libris: An 'ex-libris' (Latin for "From the Library of...") book will contain a bookplate, e.g., a small print of artwork or label attached to the inside cover that indicates the owner's name or initials. An ex-libris book will also fall under any of the aforementioned categories of conditions of use.