Example of Law

I live on my sorority's floor and there are a few understood rules that keep 24 girls in the same dorm same.
For example,
-If you leave your food out in the lounge, it's fair game. Don't want to share, don't leave it out.
-Each suite on the floor rotates on the duties of cleaning the lounge
-It's acceptable to turn up the music at night, but not during the day
-If you leave your stuff out, it will end up in the lost & found box with the other random clothes

None of these rules are actually written down anywhere. And obviously, some of the rules are more enforced and respected than others. But having a general understanding where "everyone is treated equally" and because the "laws are general, not specific", this semester has run pretty smoothly.