Section 1353.6 of the civil code prohibits governing documents of associations from banning non-commercial signs banners flags or posters in or on an owners separate interest. They may be posted in a window a door a balcony or wall of a separate interest as long as they are made of paper cardboard, cloth plastic or fabric but may not be made of lights or balloons or certain building materials and they may not be painted on an architectural surface. An association may prohibit non-commercial signs that are more than 9 square feet in size or more than 15 square feet if a banner or flag. So political signs or banners, subject to size limitations, must be allowed. Many associations use the size limitations for commercial real estate sale or lease signs also.