I have wondered this too. Maxim have documentation about the fact you can get device IDs but I've never actually worked out how to get some. I guess people did

I have wondered this too. Maxim have documentation about the fact you can get device IDs but I've never actually worked out how to get some. I guess people didn't want to be reliant on Maxim as the numbers authority? It's pretty popular for simple serial number / "Number In A Can" applications tho'.