Section 4850.5 Of Article 7. License Plates From California Vehicle Code >> Division 3. >> Chapter 1. >> Article 7.

. (a) Notwithstanding subdivision (a) of Section 4850 and Section 5200, the department, upon registering a truck tractor, shall issue to the owner one suitable license plate or other device which identifies the vehicle for which it is issued and for the period of its validity. The license plate or other device shall be attached to the front of the vehicle.
  (b) This section shall become operative only when and if the Department of the California Highway Patrol implements a program which requires identifying numbers on the right and left sides of truck tractors.