No person, except a public officer or any employee in the performance of a public duty, shall fasten any sign or notice or any kind on any curbstone, lamppost, pole, street or sidewalk surface, bridge or tree upon a public street. This prohibition is not to be construed as prohibiting signs or notices indicating danger or aides to service or safety, or subdivision identification signs which are to be erected with the written permission of the City Administrator. This prohibition includes, but is not limited to, advertisement, announcements of buildings or land for sale or rent, garage sales, private picnics and election campaign posters.