In any discontinued action, the attorney for the plaintiff shall file a stipulation or statement of discontinuance with the clerk of the court within 20 days of such discontinuance. If the action has been noticed for judicial activity within 20 days of such discontinuance, the stipulation or statement shall be filed before the date scheduled for such activity.
N.Y. Comp. Codes R. & Regs. Tit. 22 § 210.16