It also means that spare pallets take the most economical route from a retailer's loading dock back to a warehouse or factory that is shipping out goods.

FORBES: Beast of Burden

"A lot of writers don't know about this market, " he was saying as he backed the Penske truck into a dock at a Yale warehouse and delivered Mr. Momaday's crates into the hands of their buyers.

WSJ: As Trash Goes, Authors' Clutter In the Right Hands Is Very Bankable