I S B N for Books?

In a micro servicus world, one of the things is that you have things happening in various places. So how do you then tell difference between them? And by the way, isbens are an incredibly difficult, nuanced, hard thing,. That's where the book community got together as ad men. We're just really confused about all our books. Let's put a number, an em and thn. You can even talk about pre isbin, i s b n.