Tex. Occ. Code § 901.158
The board in its rules of professional conduct may regulate the competitive practices of a license holder as necessary to ensure that the license holder does not engage in a competitive practice that:
Acts 1999, 76th Leg., ch. 388, Sec. 1, eff. Sept. 1, 1999.
Amended by Acts 2001, 77th Leg., ch. 1497, Sec. 7, eff. Sept. 1, 2001.