the casino magic in biloxi uses them for both slot and room key it says so on the back. was just at harrah's laughlin got a lot of different room keys from the front desk. they did mention they had a card that they kept locked up in the safe. but no clue what it looked like. did happen to find a platinium card laying on the floor. of all places. looks just like the one in your scan even got the exp date 03/00 could use the other card. have a $5 and $25 card comming from turning stone casino.