Is this your first time using a credit card? In fact, every document will be there (see picture, my sister signed it a few days earlier)

It doesn't have any special meaning at all, just like the bottom of general documents will be printed with "goods will not be exchanged when going out" for protection. Now explain. ...

The money has been paid by the cardholder according to the correct procedures, authorized to pay for the purchase of products, based on legal credit card terms and so on.