Over the last couple of weeks I’ve held sessions on Twitter called #ISBNhour, where I invite publishers to bring their issues with ISBNs to the ongoing conversation. After the last session, it dawned on me that many people are confusing “identifying” with “describing”.
Identifiers traditionally do just that - they name something. Usually they name it with a number. Your social security number, for example, is an identifier. It means you - in a certain context. A license plate is an identifier - it means your car. These numbers may have some internal significance - state of issue, year of birth, etc. - but most people don’t really think about that. They just use the numbers when they are called upon to identify themselves or their cars.
Other identifiers - phone numbers, for example - are similar. Yes, we have area codes that used to mean something hard and fast - 212 was Manhattan, 718 was Brooklyn - but increasingly even those numbers are losing meaning. I live in Brooklyn, and while my land line has a 718 area code, I know other homes’ land lines are now prefixed by 347. Which until recently was purely a cell phone prefix. My own cell phone prefix is 917 - which used to mean Manhattan. But my oldest daughter’s cell phone is prefixed with 917, and she lives in Brooklyn; my younger daughter’s cell phone is prefixed by 718, which used to be exclusively for land lines. And the reason we stop caring so much about area codes is because we have everybody on speed dial anyway. The area code - as an human-interpretable piece of data - has become irrelevant.
ISBNs have followed a similar path. I think the publisher prefix is unnecessarily confusing now that we have so many many publishers. And of course, there are now so many books on the market (around 500,000/year at last count), that publishers cannot be guaranteed to get the same prefix when they buy a new block of numbers. Increasingly, the ISBN is becoming what it should have been all along - a dumb number.
Attaching too much meaning to your prefix is, for a publisher, a misunderstanding of what the ISBN is supposed to do. The ISBN merely identifies your product - that identification is fairly meaningless without metadata to describe that product. Just as my phone numbers inherently mean very little without my first and last names - yes, you can dial those numbers, but unless you know who is supposed to pick up on the other end, those numbers and the dialing thereof just won’t mean a whole hell of a lot to you.
The ISBN identifies - the metadata describes. So your ONIX data (or whatever it is that you’re sending to Bowker, your distributor, libraries, what have you) is what will tell those recipients “this is a PDF”, “this is an EPUB file”, “this is a trade paperback”. We don’t need to append suffixes to ISBNs - that’s making an identifier do the work of metadata. The identifier is just a number that says “this product is not that product - it is itself.” Just as a license plate says, “This car is not that car” - and doesn’t describe what KIND of car you’ve got. Just as a phone number says, “This is a number you can dial - it is not another number.” Identifiers say, “This is itself”. Descriptors - metadata - say, “These are the properties of that thing you’ve just pointed at.”
When you buy ISBNs these days, you get the ability to upload descriptors - the metadata about your books - and create what Bowker calls “title cards”. These web pages are crawl-able - meaning that Google picks them up. ISBNs plus metadata are extremely powerful tools - combining them assures that search results unambiguously turn up the products they are supposed to turn up…and readers won’t get the wrong number.

