California Code, Civil Code - CIV § 6702

(a) Except as required for the protection of the public health or safety, no governing document shall limit or prohibit, or be construed to limit or prohibit, the display of the flag of the United States by a member on or in the member's separate interest or within the member's exclusive use common area.

(b) For purposes of this section, “display of the flag of the United States” means a flag of the United States made of fabric, cloth, or paper displayed from a staff or pole or in a window, and does not mean a depiction or emblem of the flag of the United States made of lights, paint, roofing, siding, paving materials, flora, or balloons, or any other similar building, landscaping, or decorative component.

(c) In any action to enforce this section, the prevailing party shall be awarded reasonable attorney's fees and costs.