California Code, Business and Professions Code - BPC § 450

(a) An employer, or an officer, director, or substantially full-time representative of an employer or group of employers, of any licensee of a board, except that this subdivision shall not preclude the appointment of a person who maintains infrequent employer status with a licensee, or maintains a client, patient, or customer relationship with a licensee that does not constitute more than 2 percent of the practice or business of the licensee.

(b) A person maintaining a contractual relationship with a licensee of a board that would constitute more than 2 percent of the practice or business of the licensee, or an officer, director, or substantially full-time representative of that person or group of persons.

(c) An employee of a licensee of a board, or a representative of the employee, except that this subdivision shall not preclude the appointment of a person who maintains an infrequent employee relationship or renders professional or related services to a licensee if the employment or service does not constitute more than 2 percent of the employment or practice of the member of the board.