Yard

A system of tracks within defined limits, whether or not part of a terminal, designed for switching services, over which movements not authorized by time table or by train order may be made, subject to prescribed signals, rules and requirements. (AAR1)

A system of auxiliary tracks used exclusively for the classification of passenger or freight cars according to commodity or destination; assembling of cars for train movement; storage of cars; or repair of equipment. (49CFR223)

A system of tracks, other than main tracks and sidings, used for making up trains, storing of cars and for other purposes.