Examples:
ISBN format reference
- ISBN-10: 10 digits, checksum uses weights 10-2, modulo 11 (last digit may be X = 10)
- ISBN-13: 13 digits, prefix 978 or 979, checksum uses alternating weights 1 and 3, modulo 10
- Both formats encode: prefix + registration group (country/language) + publisher + title + check digit
- Books published since 2007 typically use ISBN-13. Older books may have ISBN-10 only
Group prefix samples
- 0, 1 — English (US, UK, AU, etc.)
- 2 — French
- 3 — German
- 4 — Japanese
- 5 — Russian
- 7 — Chinese
- 978-7 / 979-7 — Chinese (ISBN-13 prefix variants)