The meaning of a string of codes in the upper right corner of the back of the card:
The first letter or Chinese character is the business card printing manufacturer.
Intermediate number: refers to the production time and batch, but the first four digits are year and month, and the first digit is year and month.
Suffixes: some at the end are not.
There are two forms of magnetic stripe: ordinary magnetic stripe and strong magnetic stripe.
Strong magnetic type improves reliability because it reduces the chance of information being smeared or damaged. High cobalt element refers to the composition of magnetic stripe, which is of strong magnetic type. At present, new bank cards are generally HiCo, and those without HiCo are ordinary magnetic strips.