N.Y. Elec. Law § 8-708

§ 8-708. Early voting by mail; method of. The early mail voter shall\nmark an early mail ballot as provided for paper ballots or ballots\nprepared for counting by ballot counting machines. They shall make no\nmark or writing whatsoever upon the ballot, except as above prescribed,\nand shall see that it bears no such mark or writing. They shall make no\nmark or writing whatsoever on the outside of the ballot. In cases where\nthe express intent of the voter is unambiguous, any stray marks or\nwriting shall not be a basis for voiding a ballot. After marking the\nballot or ballots they shall fold each such ballot and enclose them in\nthe envelope and seal the envelope. They shall then take and subscribe\nthe oath on the envelope, with blanks properly filled in. The envelope,\ncontaining the ballot or ballots, shall then be mailed or delivered to\nthe board of elections of the county or city of their residence.\n