1, the bank card does not start with b, and the mechanism card punching starts with 6.

2. First of all, it is clear that there are only numbers and no letters on the bank card.

3. The fundamental reason why the number 6 is in the form of lowercase letter B is to facilitate identification and copying and reduce errors.

4. Credit cards have a way of pressing single transactions, that is, using the information protruding from the front of the credit card to press out the information on the pressure-sensitive documents. When printing 6 and 9, it is easy to be confused with 8 because of handwriting defects, so it is safer to use special fonts.