Trying to understand the basic primitives of banking is hard. When I lived in the US I asked my bank for documentation on how their stuff works.. I've done the

Trying to understand the basic primitives of banking is hard. When I lived in the US I asked my bank for documentation on how their stuff works.. I've done the same in Denmark. I've never been able to get authoritative documentation that explains IBAN, routing/account numbers, transfer types, checks, signatures, credit/debit cards, etc. I'm effectively left guessing, my bank can't even tell me if a given kind of number is secret or security sensitive. How do you find out? Where is the authoritative documentation? The man page? The RFC?