noun - refers to one's right to leave either an Elective class or Honors/AP Class (usually to go to the easier classes). The prolific statement comes from one of Ian Terry's rants.
Ian: I don't get why so many people complain about Ms. Kostelic. If they think she's too difficult, nobody is keeping them in French 3 against their will. They have a right to the door. Walk out and go to another elective or a study hall.