When two or more rates are named for the same commodity over the same route and under similar conditions, and the application is dependent upon the quantity of the commodity shipped, the total freight charges assessed against the shipment may not exceed the total charges computed for a larger quantity, if the rate specifying a required minimum quantity either weight or measurement per container or in containers and if the minimum set forth is met or exceeded.

At the shipper's option, a quantity less than the minimum level may be freighted at the lower rate if, the weight or measurement declared for rating purposes is increased to the minimum level.