California Code, Government Code - GOV § 434.5

(1) “Legal right” means the freedom of use and enjoyment generally exercised by owners and occupiers of land.

(2) “Local government agency” means a county, city, whether general law or chartered, city and county, town, municipal corporation, school district or other district, political subdivision, or any board, commission, or agency thereof, or other local agency.

(b)(1) No person, private entity, or governmental agency shall adopt any rule, regulation, or ordinance, or enter into any agreement or covenant, that prevents any person or private entity that would otherwise have the legal right to display a Flag of the United States on private property from exercising that right, unless it is used as, or in conjunction with, an advertising display.

(2) Nothing in this subdivision shall be construed to prevent a city, county, or city and county from imposing reasonable restrictions as to the time, place, and manner of placement or display of a Flag of the United States when necessary for the preservation of the public's health, safety, or order.

(c)(1) A local government agency may not adopt any policy or regulation that prohibits or restricts an employee of that agency from displaying a Flag of the United States, or a pin of that flag, on his or her person, in his or her workplace, or on a local government agency vehicle operated by that employee.

(2) Nothing in this subdivision shall be construed to prevent a local government agency from imposing reasonable restrictions as to the time, place, and manner of placement or display of a Flag of the United States when necessary for the preservation of the order or discipline of the workplace.