Any agency within the department may promulgate regulations requiring licensees to include their license numbers in any advertising, soliciting, or other presentments to the public.
However, nothing in this section shall be construed to authorize regulation of any person not a licensee who engages in advertising, solicitation, or who makes any other presentment to the public on behalf of a licensee. Such a person shall incur no liability pursuant to this section for communicating in any advertising, soliciting, or other presentment to the public a licensee's license number exactly as provided by the licensee or for failure to communicate such number if none is provided by the licensee.
Ca. Bus. and Prof'l. Code § 137