Secret Stuff in Bar Codes, Part 1:
The bar codes that are printed on comic books come in a couple of different formats, the most common being “EAN13” (+2/+5). Today’s tech tip focuses on a particular kind of EAN13 code, the “Bookland” style used for books and trade paperbacks. Note: This tip also applies to the closely-related UPC-A codes (a subset of the EAN13 format).
When the first three digits of the main barcode are “978” the barcode is in what’s known as “Bookland” style. Here, the barcode encodes the ISBN number, followed by the suggested retail price in the five digit supplemental (the smaller bars at the far right). The first digit of those five indicates the currency (0 = British £, 5 = US $), and the remaining four are the price.
Here’s the barcode for Essential X-Factor #2 :
Following the 978, you’ve got the ISBN: 078512099 minus its “check digit” of “8”. The “5” in the barcode is actually the barcode’s check digit. (I’ll likely talk more about check digits in a future tech tip). Looking at the last five digits—the supplemental—you’ve got a “5” indicating that the price will be in US dollars, followed by the price itself: “1699”, or $16.99.
Now you know where the magic comes from if you’ve ever scanned in a trade paperback’s barcode and seen ComicBase 11 automatically fill in its cover price and ISBN—all that information was right in the barcode!
Incidentally, if the supplemental is “90000”, it means that there is no suggested price for this item. Also, since there are only four digits to use for price, it means that the highest price you can have on a book using this system is $99.99.