The demise of Shelfie, a tool that allowed customers to link their print books to e-books, got me thinking about bar codes. Obviously, one method of linking print to its digital metadata is through its identifier. For print books, the identifier is the ISBN, which (since the early 2000s) is 13 digits long and can be expressed as a bar code: the EAN. Bar codes allow users to scan books, check some of the metadata (such as price) online, and make purchasing decisions—and they are frequently used by resellers prowling thrift shops and library sales, looking to pick up a good deal (an application that is looked down upon in the industry).

The book business sneered at bar codes for a long time. Cover designers didn’t like the way they marred cover art. The very idea of printing pricing information on a book cover was anathema to publishing’s vision of itself as somehow above commerce (though that did become a consumer requirement, which is why hardcover book jackets print the price on the inside front flap). But as bookstores such as Barnes & Noble, Borders, and Books-A-Million expanded and books began to be sold in other venues such as supermarkets, drugstores, and airports, publishers had to get involved with bar codes. In 1985 BISG published guidelines for bar codes on book jackets. At that time, the EAN had not yet been invented.

Bar codes as we know them were invented (and patented in 1952) for the grocery business. They began to be implemented in the 1970s, when the UPC was developed. Magazines began to use them. In fact, George Wright III, founder of PIPS (Product Identifier and Processing Systems) and an original member of BISG, invented the two- and five-digit price-add-on codes for the UPC. The effectiveness of the bar code gave rise to efficiencies that other industries had been looking for, so soon the code gained traction in other types of stores as well.

UPC bar codes began to appear on books at first in sticker form, and it was the job of the receiving clerks at large bookstores to print the stickers and apply them to book covers. But as the large book chains gained more power, they began to campaign for publishers to take on this responsibility themselves, so publishers gave in and began printing covers with the bar codes already on them.

And now we come to “Bookland.” The EAN bar code, which was gaining popularity, reserved a prefix to designate a country code. In the 1990s, Wright convinced the group that maintained the EAN to implement a “Bookland” code to indicate a book or book-related product from any country; 978 and 979 became the codes to designate products from Bookland.

EAN began as the European article number, a European version of the UPC that came in eight- and 13-digit schemas. UPC codes for books had 12 digits. The EAN organization realized that it could incorporate the ISBN of a book into that book’s EAN by using the Bookland prefix, and books could be easily scanned worldwide. But this would require publishers to change their ISBNs from the historical 10 digits to 13-digit identifiers.

In the late 1990s and early 2000s, the ISBN standard was modified to reflect its new compatibility with the EAN, and BISG began a large educational effort to persuade publishers to convert their ISBNs to 13 digits (my first consulting engagement)—a nontrivial task, as so many publishing systems had fixed-width ISBN fields. (A small aside: never design your systems so that the field that contains identifiers is fixed-width. They will break every time.)

There’s a common misconception that the reason the industry converted from 10- to 13-digit bar codes is that we were “running out of numbers.” I don’t know how that rumor got started, but even the BISG website touted it at one point. We converted to conform with a standard that was being adopted globally: the International ISBN Agency had agreed to make the change, and American publishers had to fall in line if they wanted to keep using the standard. Given that the book industry depended on ISBN more than any other identifier—it was baked into the supply chain at that point—the business had to confirm or reinvent the wheel.

The ISBN has been a groundbreaking identifier in many ways, and encoding it into a bar code is one of the smartest things this industry has ever done. Other industries have looked to the ISBN as an example, which is how we’ve gotten the ISSN, the DOI, the ISRC, and other identifiers.