Maybe the best way to refer to this stuff would be as a "Casino Card" - i.e., a card issued by the casino for purposes of tracking, identification or any other reasons that do not come to mind right now. A "Slot Card" (a card that is designed to be placed into a slot machine reader when playing) would be the main sub-category of the overall "Casino Card" area. This would make sense, but since people have started refering to all collectable cards as a "slot card," we are saddled with this difference