[sevenseventen]

The point is not just to have universally unique identifiers, but to collect common metadata that's associated with the identifiers. Like this:

https://www.bowker.com/siteassets/files/pdf-files/datasubmis...

Since this is the second time I've mentioned Bowker, let me just say that I do not and have never worked for them or with them, although I did meet with their reps several times when I worked in a different part of digital publishing. It's just that they're inescapable when you're talking about ISBNs.