Copyright law requires that copies or phonorecords deposited in the Copyright Office be of the best edition of the work. Section 101 of the 1976 Copyright Act defines the term best edition of a work as When two or more editions of the same version of a work have been published, the one of the highest quality is generally considered to be the best edition. In judging quality, the Library of Congress will adhere to the criteria set forth below in all but exceptional circumstances. When the best edition of a work is a machine-readable copy, the following criteria are applied: A. Computer Programs