Very Fine or VF is to be used only when the book is in the same immaculate condition in which it was published. There can be no defects, no missing pages, no library stamps, etc., and the dust jacket (if it was issued with one) must be perfect without any tears. (It is equivalent to As New or Mint.)
Fine approaches the condition of Very Fine, but without being crisp. For the use of the term Fine there must also be no defects, etc.
Near Fine or NF describes an attractive book with only minor flaws or light wear. Any defects must be noted.
Very Good or VG can describe a used book that is generally attractive but has some flaw (light chipping, foxing, small tears, etc.) or merely an accumulation of general wear.
Good describes the average used and worn book that has all pages or leaves present.
Fair is a worn book that has complete text pages (including those with maps or plates) but may lack endpapers, half-title, etc. (which must be noted). Binding, jacket (if any), etc., may also be worn.
Poor describes a book that is sufficiently worn that its only merit is as a Reading Copy because it does have the complete text, which must be legible. Any missing maps or plates should still be noted. This copy may be soiled, scuffed, stained or spotted and may have loose joints, hinges, pages, etc.
Our terms, with some slight alterations, are based upon those created by the AB Bookman's Weekly (aka Antiquarian Bookman) in 1949.