The barcode at the back of a physical license card has all sorts of information that may not be printed at the front. For example, for noncitizens in the US it

The barcode at the back of a physical license card has all sorts of information that may not be printed at the front. For example, for noncitizens in the US it can have some information about visa status. If there is a standard (name, DOB, photo, address, height, weight) that's probably more than enough.