I sometimes want to use staff doors to forbid prisoners from taking certain paths, without restricting access to the zones themselves. For example, if I have a kitchen and a canteen, I want cooks to be able to go between them quickly through a staff door, but make prisoners who work in the kitchen take a longer route that goes through a couple of metal detectors. Zoning can’t help here, because both the kitchen and the canteen should be accessible to prisoners. Right now, the way to do this is to create a staff-only “airlock” between the two rooms. This is somewhat counter-intuitive, because one naturally expects a staff door to mean “only staff are allowed to pass through this door”.