What to write on the magnetic stripe on the discount card?

Question

Programming

Good day to all!
We make a discount card on behalf of the company. All partners will have different discounts.
It is necessary that the card is valid in supermarkets and other places with which an agreement has been concluded.
I re-read the information and roughly understood that any of the 3 tracks of the magnetic stripe can be used to record data. You need to write down the data to which you would like to get instant access. So here's the question.
I composed the text of the first track like this:
%OOODAF=28956B000010?
Here OOODAF is the name of the company, 28956 characters before the card number, so that you can’t just manually enter the card number to the cashier and get a discount, B000010 is the card number, respectively.
Tell me if this entry is correct and will it be possible to read it normally in the future, understand and process supermarket programs, etc.? Is this information enough for them or not? Can anyone come across?

Answer 1

Doing it for myself, I would add not the magic 28956, but the control hash (salt + number). Well, for a group of companies - you need to look at the requirements of the others, what tracks and in what formats they use.