Carrier Rules:

For extra speedy delivery known as inter-modal overnight, corrugated boxes can be used to ship products by air, truck, rail, or by a combination of means. Carriers enforce packaging rules in exchange for accepting liability for the articles they transport. Carriers reserve the right to decline articles they consider inadequately packaged. Simply put, if you wish for your package to be insured by the carrier, you must obey their regulations.
Many transportation methods are not specifically covered by the rules. Over the past fifty years or more, the terminology and material requirements used in the carrier rules have become de facto standards for corrugated and solid fiber boxes. Carrier rules address only the concerns associated with their mode of transportation- not the storage, display, or further distribution of boxes. Once all of these factors are taken into account, boxes may not only need to meet the carrier standards, but exceed beyond them.