Idaho Code § 37-2504: Oil to be labeled.

Gasoline, benzine, naphtha, lubricating oil and grease, road oil, bituminous road materials, diesel fuel and fuel oil must be sold under their true name and grades, respectively, and such names and grades must be impressed or otherwise plainly marked upon the barrel, can, vessel, or other container in which the same is stored, sold, offered or exposed for sale, respectively, or upon a label conspicuously and securely fastened thereto, giving the true name and grade of the product, name and address of manufacturer or dealer, who sells the same.