Complete Fairfax CCounty Code: http://www.municode.com/resources/gateway.asp?pid=10051&sid=46
Section 82-5-19. Parking for certain purposes prohibited.91
91. For state law authorizing counties to prohibit parking of vehicles for commercial purposes, see Va. Code Ann. § 46.2-1224.
(a) It shall be unlawful for any person:
(1) To park or place any automobile, truck, trailer or other vehicle upon or in any street, alley or parkway for the purpose of selling or offering the same for sale or rent;
(2) To attach or place any sign or lettering upon any automobile, truck, trailer or other vehicle parked in or upon any public street, alley or parkway indicating that such vehicle is offered for sale or for rent;
(3) To park any vehicle from which any merchandise is being sold upon any street in a business district;
(4) To stop a vehicle at any time upon the highway for the purpose of advertising any article of any kind, or to display thereupon advertisements of any article or advertisement for the sale of the vehicle itself. (3-13-69; 1961 Code, § 16-123.)