Section 317.017 - Participants, required minimum age - surety bond requirements - elbow and knee strikes to head prohibited, when1. In any professional or amateur event the division regulates, other than amateur kickboxing, no person shall be allowed to participate if such person is not eighteen years of age or older on or before the day the individual is scheduled to participate in the event.2. Before the office issues a promoter's license, the promoter shall provide the office a surety bond in the amount of twenty-five thousand dollars or an irrevocable letter of credit in the amount of at least twenty-five thousand dollars from a lending institution approved to do business in the United States to guarantee payment of all state athletic taxes and fees to the state. The surety bond or irrevocable letter of credit shall cover all license fees and taxes due to the office as well as all expenses of the contestants and officials in the event of default by the promoter. The irrevocable letter of credit shall be released only upon written approval by the office. An additional bond or irrevocable letter of credit may be required in the amount specified by the office if it may be reasonably expected that the twenty-five thousand dollar bond or irrevocable letter of credit will not provide sufficient protection to the state. It shall be the duty of each promoter to maintain all required bonds on a current status.3. There shall be a prohibition of all elbow strikes to the head of an opponent during an amateur mixed martial arts bout.4. For the first five sanctioned amateur bouts, there shall be a prohibition of knee strikes to the head of an opponent during an amateur mixed martial arts contest. However, after the fifth sanctioned bout for both contestants, both contestants may mutually agree to allow knee strikes during a bout.Added by 2018 Mo. Laws, HB 1388,s A, eff. 8/28/2018.