3107.6.5 Signs on vacant property. Display of any sign, poster, or other advertising medium on or in any part of a vacant building, store, or premises, visible from the street or public way, other than real estate signs, complying with Section 3107.16 and authorized billboards or poster panels, is prohibited.
Exception: One sign not more than 6 square feet (0.557 m²) in area giving the name, business, and new address of the former occupant is permitted to be displayed for not more than 60 days on the vacated premises.
District of Columbia Building Code Supplement of 2003
See page 173.