Mich. Comp. Laws § 207.1115

Sec. 115. (1) A supplier operating a fuel transportation vehicle on the public roads or highways of this state shall display on the vehicle, in colors that distinctly contrast with the color of the vehicle and in letters and figures not less than 3 inches high, the supplier's name and the license number identified as Mich. Supplier No. ___. (2) A person other than a supplier operating a fuel transportation vehicle on the public roads or highways of this state shall display on the vehicle, in colors that distinctly contrast with the color of the vehicle and in letters and figures not less than 3 inches high, the person's name and the license number identified as Mich. MFTA No. ___.