Iowa Code § 327D.10: Unjust discrimination — exceptions.

If any common carrier subject to the provisions of this chapter shall directly or indirectly, by any special rate, rebate, drawback, or other device, charge, demand, collect, or receive from any person or persons a greater or less compensation for any service rendered, or to be rendered, in the transportation of passengers or property subject to the provisions of this chapter, than it charges, demands, collects, or receives from any other person or persons for doing a like and contemporaneous service in the transportation of a like kind of traffic, such common carrier shall be guilty of unjust discrimination, which is hereby prohibited and declared to be unlawful; but this section shall not be construed as prohibiting a less rate per one hundred pounds in a carload lot than is charged, collected, or received for the same kind of freight in less than a carload lot.