N.Y. Public Buildings Law § 141

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