A way to encode the ISBN in EAN bar codes. The EAN code is formed by putting the numbers 978 in front of the ISBN. Leave out the tenth digit in the ISBN and calculate the check digit for the EAN, et voila.

Bookland codes can also carry pricing information. This is done with a separate bar code, usually placed to the right of the EAN code. However, most books carry pricing code 90000, meaning the recommended price is unknown.