California Code, Business and Professions Code - BPC § 18731

(a) In addition to the other requirements of this chapter and regulations adopted thereunder, no referee or physician and surgeon shall be assigned to a boxing contest if he or she has not completed a clinic offered by a provider approved by the commission.

(b) A referee or physician and surgeon shall complete a clinic within the preceding six months of a boxing contest.

(c) The commission shall approve a clinic provider if the clinic includes, at a minimum, but is not limited to, the following topics related to a boxing contest:  the subjects of the rules of the commission, the recognition and diagnosis of serious or life-threatening, boxing-related and neurological injuries and disorders, and refereeing a bout.

(d) The clinic provider may charge a referee or physician and surgeon participating in a clinic a fee in an amount not to exceed the reasonable cost of the clinic.

(e) Nothing in this section shall be construed to prohibit the commission from offering a clinic subject to the requirements of this section.