((a)) Whenever standards relating to kind, class, quality, or condition of grain are effective under for any grain no person shall in any sale, offer for sale, or consignment for sale, which involves the shipment of such grain in interstate or foreign commerce, describe such grain as being of any grade in any advertising, price quotation, other negotiation of sale, contract of sale, invoice, bill of lading, other document, or description on bags or other containers of the grain, other than by an official grade designation, with or without additional information as to specified factors: , That the description of such grain by any proprietary brand name or trademark that does not resemble an official grade designation, or with respect to interstate commerce, by the use of one or more grade factor designations set forth in the official United States standards for grain, or by other criteria shall not be deemed to be a description of grain as being of any grade.
((b)) No person shall, in any sale, offer for sale, or consignment for sale, of any grain which involves the shipment of such grain from the United States to any place outside thereof, knowingly describe such grain by any official grade designation, or other description, which is false or misleading.