This is an interesting idea, I’m not really familiar with the use of readers, I imagine it would require special hardware or perhaps a smartphone app that sends the read data as a request to the server.
The cards are pretty simple, they come pre programmed with a code/encryption on them and you require a card reader, that takes the information from the card.
If my understanding is correct the card reader, normally connected via USB sends the data to the pc in text format, the same as if you were to type the data with a keyboard.
I’m no expert but I guess it would require some code to link the data sent from the card reader with a field on each members profile/account and then make that field searchable when the card is swiped again through the card reader.
I guess this feature would be ideal for physical locations & clubs with memberships or groups that require registration/ sign in