This differs from the Emergency Door Release or Egress that can be used by the general public in case of an emergency, this usually requires a cover to be removed or broken to operate and would never usually be used in the normal course of a journey.
The location of the local door varies and is usual in multiple locations on the train, and sometimes does not require a switch to operate in the case of outside doors to Brake Vans or Driving Van Trailers for example.
Brake Van doors and control panel covers for instance require keys to open, and in the case of door control panels require another key to prime them for use.
Local door switches in the open position while disarmed usually activate the train's emergency braking systems; this prevents a door from opening by accident when a crew member arms the control while in motion.
Local instructions allow the Guard to operate train doors from any location it is safe to do so, or where regulations require them to do so.