Cal. Bus. & Prof. Code § 2474

Any person who uses in any sign or in any advertisement or otherwise, the word or words “doctor of podiatric medicine,” “doctor of podiatry,” “podiatric doctor,” “D.P.M.,” “podiatrist,” “foot specialist,” or any other term or terms or any letters indicating or implying that he or she is a doctor of podiatric medicine, or that he or she practices podiatric medicine, or holds himself out as practicing podiatric medicine or foot correction as defined in Section 2472, without having at the time of so doing a valid, unrevoked, and unsuspended certificate as provided for in this chapter, is guilty of a misdemeanor.