Tex. Transportation Code § 721.004: INSCRIPTION REQUIRED ON MUNICIPAL AND COUNTY-OWNED MOTOR VEHICLES AND HEAVY EQUIPMENT.

(a) The office having control of a motor vehicle or piece of heavy equipment owned by a municipality or county shall have printed on each side of the vehicle or equipment the name of the municipality or county, followed by the title of the department or office having custody of the vehicle or equipment.

(b) The inscription must be in a color sufficiently different from the body of the vehicle or equipment so that the lettering is plainly legible.

(c) The title of the department or office must be in letters plainly legible at a distance of not less than 100 feet.

Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995.