No person required to be licensed by this chapter shall perform or attempt to perform the acts so licensed by ringing the doorbell or knocking at the door or otherwise calling attention to his presence of, or at, any residence where a sign bearing the words "No Peddlers," or words of similar import, is painted or affixed so as to be exposed to public view and no such person shall perform or attempt to perform any of such acts in any building, structure or place of business whereon or wherein a sign bearing the words "No Peddlers," or words of similar import, is painted or affixed so as to be exposed to public view.  (Prior code § 17-14)