N.Y. New York City Civil Court Law § 802

§ 802. Tender and offer. The provisions of Rules 3219, 3220 and 3221\nof the CPLR, treating respectively of tender, offer to liquidate damages\nconditionally and offer to compromise, shall be applicable in this\ncourt, with the additional requirement that at the time of service upon\nthe other party of the "written tender", "written offer" or "written\nnotice", as referred to in said rules, a copy of such tender, offer or\nnotice shall be filed with the clerk.\n