Nothing contained in this chapter shall apply to any public officer or officer of any court, who in pursuance of his duty as such officer, conducts within the city an auction sale pursuant to any law of the state or of the United States of America, or the lawful order of any court, nor to the sale or offering for sale of unredeemed pledges in the manner provided by law, by pawnbrokers, loan companies or others, the sale or offering for sale for the purpose of satisfying a lien, or any other sale or offering for sale at auction where the same is specifically authorized or provided by law. (Prior code § 7.24.140)