It is unlawful for any person to construct, erect or maintain any streamers, banners or signs, or suspend the same over any public street or alley of the city without obtaining a permit so to do from the city council, applications for which shall specify the width and length of the streamers, banners or signs, the height the same shall be suspended from the pavement and the length of time the same is desired to remain. (1990 Code § 12.04.100)