Cal. Business and Professions Code § 4980.48

(a) A trainee shall, prior to performing any professional services, inform each client or patient that the trainee is an unlicensed marriage and family therapist trainee, provide the name of the trainee’s employer, and indicate whether the trainee is under the supervision of a licensed marriage and family therapist, a licensed clinical social worker, a licensed professional clinical counselor, a licensed psychologist, a licensed physician certified in psychiatry by the American Board of Psychiatry and Neurology, or a licensed educational psychologist. (b) Any person that advertises services performed by a trainee shall include the trainee’s name, the supervisor’s license designation or abbreviation, and the supervisor’s license number. (c) Any advertisement by or on behalf of a marriage and family therapist trainee shall include, at a minimum, all of the following information: (1) That the trainee is a marriage and family therapist trainee. (2) The name of the trainee’s employer. (3) That the trainee is supervised by a licensed person.