New York Laws
Article 5 - Public Buildings Generally
141 - Display of Foreign Flags on Public Buildings.

ยง 141. Display of foreign flags on public buildings. It shall not be
lawful to display the flag or emblem of any foreign country upon any
state, county or municipal building; provided, however, that whenever
any foreigner shall become the guest of the United States, the state or
any city, upon public proclamation by the governor or mayor of such
city, the flag of the country of which such public guest shall be a
citizen may be displayed upon such public buildings.