Section 501.155 - Voluntary Guidelines(a) The executive council may cooperate with an agency that is not subject to this chapter to formulate voluntary guidelines to be observed in the training, activities, and supervision of persons who perform psychological services.(b) Except as provided by Subsection (a), the executive council may not adopt a rule that relates to the administration of an agency that is not subject to this chapter.Amended by Acts 2019, Texas Acts of the 86th Leg.- Regular Session, ch. 768,Sec. 2.010, eff. 9/1/2019. Acts 1999, 76th Leg., ch. 388, Sec. 1, eff. 9/1/1999.