ISBN stands for International Standard Book Number. It is a unique, machine-readable identification number, which marks a book like a person's thumbprint marks that individual. This worldwide 10-digit number (soon to be 13 digit) is divided into the following four parts, each separated by a hyphen:
- Group/country identifier: identifies a national or geographic group of publishers
- Publisher identifier: identifies a publisher within a group
- Title identifier: identifies a title or edition of a title
- Check digit: single digit which validates the ISBN
U.S. publishers self book publishing should apply for ISBNs with the following agency: U.S. ISBN Agency, 630 Central Avenue, New Providence, NJ 07974, telephone: 877-310-7333, e-mail: isbn-san@bowker.com, website: www.isbn.org.
*Their website features an online application and a printable application that you may submit through the U.S. mail. The minimum number of ISBN's that can be purchased is 10 and is soon to go to 13.