Stephen Sprunk wrote:

There is no way for the terminal to know whether the Visa/MC/etc. number
presented is a credit, debit or charge card. A card processor _may_ be
able to deduce it from other information, but only the issuing bank
knows for sure.

I have no idea how you come up with this stuff, but the type of card,
not to mention who issued it, is built into the number range itself.

Someone else can continue to argue with you. I'm bored.