36 C.F.R. § 520.10 Placards, signs, banners, and flags.
Title 36 - Parks, Forests, and Public Property
The displaying or carrying of placards, signs, banners, or flags is prohibited unless officially authorized.
Title 36: Parks, Forests, and Public Property
PART 520—RULES AND REGULATIONS GOVERNING THE BUILDINGS AND GROUNDS OF THE NATIONAL ZOOLOGICAL PARK OF THE SMITHSONIAN INSTITUTION
§ 520.10 Placards, signs, banners, and flags.
