When you're a student you get a card or pin or something to identify you to the school cafeteria. You have a balance it charges against. In theory, when it hit

When you're a student you get a card or pin or something to identify you to the school cafeteria. You have a balance it charges against. In theory, when it hits zero, no more food for you. But that's impractical because kids are bad about just about everything, and so denying food because they forgot to remind their parents to recharge the thing is harsh. So the system lets them go into "debt" and still get a lunch. And it doesn't really stop, but the school will often put up a bit of a fight over final grades or diploma to try to get the debt paid off, but often it just gets written off.