Used with NanDeck, creates Card Backs for "IDKWDYWTP?" that let you quickly find all cards for games that support a particular number of players. The back for each card has colored bars indicating the number of players to make it quick and easy to find cards for games for N players. I guess it's unusual to have backs that are different per card but in this case the cards aren’t meant to conceal anything from anyone so I figured I might as well add some helpful stuff on the back.