N.Y. Real Prop. Tax Law § 1134

§ 1134. Presumption of validity. It shall not be necessary for the tax\ndistrict to plead or prove the various steps, procedures and notices for\nthe assessment and levy of the taxes or other lawful charges against the\nparcels of real property set forth in the petition and all such taxes or\nother lawful charges and the lien thereof shall be presumed to be valid.\nA respondent alleging any jurisdictional defect or invalidity in the\ntax, or in the proceeding for the enforcement thereof, must particularly\nspecify in his or her answer such jurisdictional defect or invalidity\nand must affirmatively establish such defense. The provisions of this\narticle shall apply to and be valid and effective with respect to all\nrespondents even though one or more of them be infants, incompetents,\nabsentees or non-residents of the state.\n