Tex. Transp. Code § 681.007
A vehicle may be parked and is exempt from the payment of a fee or penalty in the same manner as a vehicle that has displayed on the vehicle special license plates issued under Section 504.201 or a disabled parking placard as provided by Section 681.006 if there is displayed on the vehicle a license plate or placard that:
Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995.
Acts 2005, 79th Leg., Ch. 728 (H.B. 2018), Sec. 20.003(f), eff. September 1, 2005.