Miss. Code § 27-31-13
All commodities, including everything movable that is of value usually bought and sold, which is in transit and assembled or in storage on wharfs, railway cars, or in warehouses, at ports of entry, designated by the U. S. government as such, in the State of Mississippi, intended for export or import into, through or from the State of Mississippi, shall be and all such commodities are exempt from all state, county and municipal taxation, including taxes levied and assessed by Section 27-65-19, Mississippi Code of 1972, on the transportation of freight thereof moving on intrastate rates therefrom; Provided, however, that the provisions of this section shall neither apply to, affect nor repeal any part of Chapter 116 of the Mississippi Code of 1930, the amendments thereof, or laws supplemental thereto, nor shall it authorize or permit the receipt into Mississippi, or storage within the state, or within the jurisdictional limits thereof, of any gasoline, kerosene, distillate, motor vehicle or internal combustion engine fuel, by whatever name called, except under the provisions of said Chapter 116, Code of Mississippi, 1930, or amendments or laws supplemental thereto, as therein set out.
It is the intent and purpose of this section to exempt from all state, county and municipal taxation, all commodities in transit, assembled and/or in storage, and/or in railway cars at any harbor or port designated by the U. S. government as a port of entry in the State of Mississippi, and thereby encourage interstate or intrastate and foreign commerce passing through the ports and harbors of the state, except as provided in the first paragraph hereof. All freight shipments of commercial fertilizers moving on intrastate rates within the state are hereby exempted from all taxes levied and assessed by Section 27-65-19, Mississippi Code of 1972.
Miss. Code § 27-31-13