Something I had to use occasionally in my retail days when our credit card system would go down. Weird to see it written about in historic terms.

These lasted much longer than the paper Warning Bulletins.

https://www.investopedia.com/terms/w/warning-bulletin.asp

I remember this from a taxi ride in the early 2000s. Even then they were pretty rare.

If I remember correctly, up through 2008 even, we would punch the card into the terminal for authorization, use the imprinter to have the customer sign and track the number, and then had to phone call the processor to capture the cards at the end of the day.

I visited Nunavut in 2019 as a researcher, the town I was in still used these at some places. Being born after their widespread use I had no idea what it was

None of the cards I have today have embossed numbers on them. Which I like as they don't leave an imprint on my wallet's leather. But to use one back in 1995 the clerk would have to hand-write all the numbers and expiration date[0] on the credit slip. A process that is fraught with error.

[0] After looking it up in the booklet of known bad cards that was mailed to the store, or calling their card processor's phone number to check.

The last time I personally witnessed one of these being used was on an Amtrak train in approximately 2006.