Texas Transportation Code - TRANSP § 502.453. Government-Owned Vehicles;  Public School Buses;  Fire-Fighting Vehicles;  County Marine Law Enforcement Vehicles;  U.S. Coast Guard Auxiliary Vehicles

(a) The owner of a motor vehicle, trailer, or semitrailer may apply for registration under Section 502.0025 or 502.451 and is exempt from the payment of a registration fee under this chapter if the vehicle is:

(b) An application for registration under this section or Section 502.0025 must be made by a person having the authority to certify that the vehicle meets the exemption requirements prescribed by Subsection (a).  An application for registration under this section of a fire-fighting vehicle described by Subsection (a)(3) must include a reasonable description of the vehicle and of any fire-fighting equipment mounted on the vehicle.  An application for registration under this section of a vehicle described by Subsection (a)(5) must include a statement signed by a person having the authority to act for a sheriff's department that the vehicle is used exclusively in marine law enforcement activities under the direction of the sheriff's department.  An application for registration under this section of a vehicle described by Subsection (a)(7) must include a statement signed by a person having authority to act for the United States Coast Guard Auxiliary that the vehicle or trailer is used exclusively in fulfillment of an authorized mission of the United States Coast Guard or Coast Guard Auxiliary, including search and rescue, patrol, emergency communications, or disaster operations.