What is an ISBN ?
An ISBN is simply an International Standard Book Number.
ISBNs were 10 digits in length up to the end of December 2006, but since 1 January 2007 they now always consist of 13 digits. ISBNs are calculated using a specific mathematical formula and include a check digit to validate the number.
Each ISBN consists of 5 elements with each section being separated by spaces or hyphens. Three of the five elements may be of varying length:
- EAN Prefix element – The International Article Number (EAN) prefix currently can only be either 978 or 979. It is always 3 digits long.
- Registration group element – this identifies the particular country, geographical region, or language area participating in the ISBN system. This element can be between 1 and 5 digits long.
- Registrant element – this identifies the particular publisher or imprint. This can be up to 7 digits long.
- Publication element – this identifies the particular edition and format of a specific title. This can be up to 6 digits long.
- Check digit – this is always the final single digit that mathematically validates the rest of the number. It is calculated using a Modulus 10 system with alternate weights of 1 and 3.
All you really need to know is that each book will have a unique number which is the number under the bar code normally found on the back bottom left or right hand corner.
What is an ISBN used for?
An ISBN is essentially a product identifier used by publishers, booksellers, libraries, internet retailers and other supply chain participants for ordering, listing, sales records and stock control purposes. The ISBN identifies the registrant as well as the specific title, edition and format.
If you would like more information on the wacky world of ISBN’s here is a link to the National ISBN Agency.