Earlier quoted context omitted.
I think you are mistaken about card rules. To protect themselves against chargebacks the merchant needs to keep a copy of the signed credit card slip, not a physical imprint of the card. That's actually better than a physical imprint (which is impossible on many cards these days anyway) because a matching signature can prove who used the card, not just that the card was physically present.
Worth looking into! Thanks. I know there's been at several cases where we specifically lost because of lack of imprint, but another thing I've learned in dealing with the credit card issuers is that, despite what we hope, there is MASSIVE inconsistency in the application of chargeback rules. Sometimes you'll lose a chargeback because the issuer just wants to be nice their cardholder (Amex is guilty of this) and they'…
I'm in the UK and this is not really my area, so you'd probably have a better chance of verifying that than me.