Tariff engineering refers to design and manufacturing decisions made primarily so that the manufactured good is classified at a lower rate than it would have been absent those decisions. It is a loophole whereby an importer pays a lower tariff by "adapting the item [being imported] so that [the importer doesn't] have to pay any levy". In contrast to , tariff engineering configures the design, material, or construction to legally achieve the desired classification rather than illegally misclassifying the product or good. For tariff engineering to be legal, the good being imported must be a "commercial reality", which means any tariff engineering must be a "genuine step in the manufacturing process" or have a commercial use or identity as imported. The rule of commercial reality limits manu