how to define a mastercard using rfid

hello, i am using an arduino mega 2560 along with rfid rc522. i checked rfid using dumpinfo program. i wanted to know how to define mastercard. And also how to add and delete a rfid tag using mastercard and delete card?

i wanted to know how to define mastercard.

What do YOU mean by "mastercard"? There is nothing magic about one card vs. another. You might assign meaning to one card that is different from the meaning assigned to other cards. We have no idea what meaning you have assigned to one specific card.

And also how to add and delete a rfid tag using mastercard and delete card?

When a tag is scanned, print the tag to the serial port. Print out the data from the serial monitor. Take it to a tattoo parlor. Get them to tattoo the numbers on you somewhere. Is that how you want to "add" a number?