BOX meaning in Regional ?

A boxcar is the North American (AAR) term for a railroad car that is enclosed and generally used to carry freight. The boxcar, while not the simplest freight car design, is probably the most versatile since it can carry most loads. Boxcars have side doors of varying size and operation, and some include end doors and adjustable bulkheads to load very large items.

Similar covered freight cars outside North America are covered goods wagons and, depending on the region, are called goods van (UK and Australia), covered wagon (UIC and UK) or simply van (UIC, UK and Australia).