I found this online today and thought I’d share. You man have noticed that new books now have a 13 number ISBN instead of 10. Here is a summary of the changes:

1. The ISBN will change from 10 to 13 digits on 1 January 2007
2. Existing ISBNs will be prefixed by 978
3. The resulting 13-digit number will be identical with the EAN-13 number that is currently encoded in the bar code
4. The 979 prefix will be introduced when the current stock of numbers is exhausted
5. Publishers’ identifier prefixes are not likely to remain the same for ISBNs using the 979 prefix
6. Bar codes will carry the 13-digit ISBN with hyphenation above the barcode and the EAN-13, the identical number without hyphens or spaces, below the bar code.