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On the sign:
WARNING! SERVICE POLICE DOGS ON PATROL Watchdog icon inside a warning triangle
The sign is next to the War Museum - the Battle of Britain Memorial Flight, a unit of the British Royal Air Force that operates historical aircraft from the Second World War.
Photographer’s Note: Military Police warning sign on a gate into the Battle Of Britain Memorial Flight. The visitor centre is located inside Royal Air Force Station Coningsby. The special RAF flight regularly flies air demonstrations with authentic Second World War era aircraft. The base is home to other active squadrons including those part of Quick Reaction Alert (air defence). Understandably security must be strictly enforced.