The rules of Notre Dame

We aren't allowed to use our mobile phones but we are allowed to bring our calling card.
We aren't allowed to run in the playground but we aren't allowed to run to school.
We aren't allowed to listen to music but we are allowed to listen to music to school.
We aren't allowed to eat and drink during the lesson , but we are allowed to eat and drink in the playground.
Boys aren't allowed to have earring but girls are allowed to.