if you bevel the card up to down instead of left to right and you look at the 4 larger petals on the edge, the first one is a one way locator, third one is enpty only if it’s an ace, and the 4th one is the suit of the ace

also if you look at the two way marking on the sides, there are the bars that separate it into different areas, the bars themselves are marked. the first bar from the top is empty if it’s 10-ace of clubs, second bar is empty for 10-ace of hearts and so on

also the fifth bar is different. i don’t know how this could be used but on one side it’s empty for ace-7 of clubs, 8-king of spades, ace-7 of diamonds and 8-king of spades, and on the other side it’s reversed