Type X where X is the number of ways through the door. Type 1 is a one way door, no return! Type 2 is a 2 way door. I’d probably label type 1 a kiki (a point

Type X where X is the number of ways through the door. Type 1 is a one way door, no return! Type 2 is a 2 way door. I’d probably label type 1 a kiki (a pointy decision … beware!)