ginger tax
Whenever a policeman comes to school (either to talk to you about careers and shit, or to arrest someone, depending on the calibre of your school), it is customary to point them out to a ginger, exclaiming "Ooh, someone hasn't paid their ginger tax!"

The ginger in question is then expected to reply "Damn, I knew I forgot something", and then spend the rest of the day in hiding. If he doesn't do this, you may hit him.
written by an*nym*us*use*, approved by Matt