Bingo ink daubers (they are so fun to use!) go in the outside pockets, or pens, markers, inside the bag goes your money, snacks or anything you want.
So many bingo places no longer use paper cards but a kind of computer thingy and IMHO it takes ALL the fun out of bingo. My friends and I used to go and have so much fun using our different colors of ink daubers to mark our paper cards.