N.Y. Gen. Bus. Law § 93

§ 93. Duplicate receipts must be marked "duplicate." A person\nmentioned in sections ninety and ninety-one, who issues any second or\nduplicate receipt or voucher, of a kind specified in those sections, at\na time while a former receipt or voucher for the merchandise specified\nin such second receipt is outstanding and uncanceled, without writing\nacross the face of the same the word "duplicate," in a plain and legible\nmanner, is guilty of a misdemeanor.\n