California Code, Business and Professions Code - BPC § 25664

(a)(1) The use, in any advertisement of alcoholic beverages, of any subject matter, language, or slogan addressed to and intended to encourage minors to drink the alcoholic beverages, is prohibited.

(2) Signage or flyers advertising an establishment that serves alcoholic beverages to individuals under the age of 21 years are prohibited under paragraph (1) if one of the establishment's principal business activities is the selling of alcoholic beverages, and the advertisement expressly states that the jurisdiction in which the establishment is located has a legal drinking age of under 21 years or that individuals under the age of 21 years may patronize the establishment.

(3) Nothing in this section shall be deemed to restrict or prohibit any advertisement of alcoholic beverages to those persons of legal drinking age.