Cal. Labor Code § 139.45

(a) In promulgating regulations pursuant to Sections 139.4 and 139.43, the administrative director shall take particular care to preclude any advertisements with respect to industrial injuries or illnesses that are false or mislead the public with respect to workers’ compensation. In promulgating rules with respect to advertising, the State Bar and physician licensing boards shall also take particular care to achieve the same goal. (b) For purposes of subdivision (a), false or misleading advertisements shall include advertisements that do any of the following: (1) Contain an untrue statement. (2) Contain any matter, or present or arrange any matter in a manner or format that is false, deceptive, or that tends to confuse, deceive, or mislead. (3) Omit any fact necessary to make the statement made, in the light of the circumstances under which the statement is made, not misleading. (4) Are transmitted in any manner that involves coercion, duress, compulsion, intimidation, threats, or vexatious or harassing conduct. (5) Entice a person to respond by the offering of any consideration, including a good or service but excluding free medical evaluations or treatment, that would be provided either at no charge or for less than market value. No free medical evaluation or treatment shall be offered for the purpose of defrauding any entity.