Gate Guard
From ARRSEpedia
Old Tank/Aircraft/item of significance to the Regiment. Placed there to show Civvies that the unit once operated the vehicle/aircraft. Costs a fortune in maintenance and painting despite the fact that it is only a hull/Airframe.
Is often the target of inter-unit Pranks. However, be warned, the RSM's spider sense will start tingling if anyone gets too near his Gate Guard.
