Not sure what you mean by that. Can anyone get a picture of the cards (or similar ones) because I really want to see these. They sounded so strange.
If you have a card worth 10 in blackjack (10, Jack, Queen, King) it will read in the scanner that just looks at a corner of a card. If it's anything else, the pip is in a different location, and won't show when you put the corner of the card in a reader. The blackjack dealer checks the down card on one of these readers if they have an Ace showing, so that people don't go through the whole round just to see if the dealer has a blackjack anyway.