;74xx:A GWR 7400 Class 0-6-0PT engine
;A.J.Hill:Alfred John Hill, Chief Mechanical Engineer (CME) of the Great Eastern Railway 1912-1922
;ANPR:Automatic Number Plate Recognition
;Armstrong:Joseph Armstrong, Locomotive, Carriage and Wagon Superintendent of the Great Western Railway 1864-1877
;ARPS:Association of Railway Preservation Societies