Describes performance requirements and test methods for a thief resistant mechanically operated single-point lock assembly (including locking plates, fixing screws, fitting instructions, cylinders and protective furniture where appropriate) that: a) incorporates a lock conforming to BS EN 12209 field of door application grades A, B, C, D, E, F or J, i.e. a lock that can always be unlocked from the inside without a key thereby only allowing keyless egress; and b) is used in doors, window doors and entrance doors in buildings.