Different rules apply to railroad owned cars and private owned cars.
Railroads invest capital to buy railroad owned cars. In recent years railroads have been selling cars from their fleets to equipment leasing companies. Watching a 'merchandise' train pass and you will see many 'general purpose freight cars' (Boxes, Gons, Flats, Hoppers etc.) with a reporting mark ending in X (this discounts cars such as TTX, RBOX, GONX and other Trailer Train owned cars).
Being retired, I don't know what forms of games that the carriers are playing - but from experience I know they are playing games.
