Existing law provides that every executive or ministerial officer, employee, or appointee of the State of California, or any county or city therein, or any political subdivision thereof, who knowingly asks, receives, or agrees to receive any emolument, gratuity, or reward, or any promise thereof excepting such as may be authorized by law for doing an official act, is guilty of a misdemeanor. Existing law exempts from that offense certain employment by a peace officer while off duty, as specified. Existing law also provides that a peace officer shall not be prohibited from engaging in other employment while off duty, as specified.