California Code, Business and Professions Code - BPC § 19510

(a) Every steward and racing official not required to be licensed under Article 4 (commencing with Section 19480) shall be licensed by the board pursuant to this article.  Any license issued pursuant to this article shall include a current photograph of the licensed person.

(b) No person required to be licensed pursuant to this article may participate in any capacity in any horse race meeting without a valid and unrevoked license.  The board shall determine the fixed license fee which shall be paid in order to receive a license pursuant to this article.

(c) As used in this section, “racing official” means the starter, timer, paddock judge, horseshoe inspector, horse identifier, official veterinarian, racing veterinarian, associate judge, placing judge, patrol judge, clerk of scales, clerk of the course, and any other person acting as an official at any horse racing meeting.