What is an ISBN?

The ISBN (International Standard Book Number) is a unique machine-readable identification number, which marks any book unmistakably. This number is defined in ISO Standard 2108. The number has been in use now for 35 years and has revolutionised the international book-trade. 170 countries and territories are officially ISBN members. The ISBN accompanies a publication from its production onwards.

From 1 January 2007 the number consists of thirteen digits:

• Prefix element     
• Registration group identifier
• Registrant / publisher element
• Publication element
• Check digit

The ISBN is divided into five parts of variable length, which must be separated clearly by hyphens or spaces:

ISBN  978-0-571-08988-8
or 

ISBN  978 0 571 08988 8

The number of digits in the second, third and fourth parts of the ISBN (group identifier, publisher prefix, title identifier) varies. The number of digits in the group number and in the publisher prefix is determined by the quantity of titles planned to be produced by the publisher or publisher group. Publishers or publisher groups with large title outputs are represented by fewer digits.

To get more details about the ISBN-number see the ISBN Users' Manual.

The practical aspect of ISBN?

Forget about dealing with complicated bibliographic records - it is all identified by the 10-digit number. In order to avoid mistakes, use the bar-coded form - the ISBN is easily turned into an EAN Bookland bar-code and is processed by the usual bookstore, general store or supermarket electronic systems. Books in Print catalogues and the Publishers' International ISBN Directory keep you up-to-date on title and publishers identification.