[Koha] book number format

Just an easy question. It seems that members' numbers are prefixed with the letter V. What is the prefix for book numbers? Better still what are all prefixes used by Koha? I'm just about ready to order bar codes for all of our 7000 books and want to make sure I'll get the right ones. I'm assuming that the number format and the checksum formula for members and books are the same. Thanks tomasz kotula.