ISBN is the abbreviation of International Standard Book Number - a unique, numeric commercial book identifier. The ISBN-13 specification was Issued from January 2007, and describes how the 13-digit ISBN check digit is calculated.
Valid symbols: |
0123456789 |
Length: |
fixed, 13 symbols |
Check digit: |
one, algorithm modulo-10 |
The ISBN assigned to books after 2006 contained 13 digits length and consist of four fields of variable length:
prefix: 978 or 979.
The group identifier, (language-sharing country group).
The publisher code.
The item number.
A checksum character or check digit.
A "ISBN-13" barcode.
Note the 'human readable' digits at the foot which can be used by operators if the label becomes damaged or will not scan for some reason - "978-0-306-40615-7" is a number encoded in the barcode.