Tennessee Code Title 4. State Government § 4-5-219

(a) The secretary of state, from time to time, may adopt, in accordance with the rulemaking requirements of this chapter, model rules of procedure appropriate for use by as many agencies as possible.

(b) The model rules shall deal with all general functions and duties performed in common by several agencies.

(c) Each agency shall adopt as much of the model rules as is practicable. To the extent an agency adopts the model rules, it shall do so in accordance with the rulemaking requirements of this chapter.

(d) Any rule or procedure adopted by an agency that differs from the model rules shall be accompanied by a finding stating the reasons why the relevant portions of the model rules were impracticable for such agency.