N.Y. CVP Law § 306

Rule 306. Proof of service. (a) Generally. Proof of service shall\nspecify the papers served, the person who was served and the date, time,\naddress, or, in the event there is no address, place and manner of\nservice, and set forth facts showing that the service was made by an\nauthorized person and in an authorized manner.\n (b) Personal service. Whenever service is made pursuant to this\narticle by delivery of the summons to an individual, proof of service\nshall also include, in addition to any other requirement, a description\nof the person to whom it was so delivered, including, but not limited\nto, the process server's perception of the person's: gender, race, hair\ncolor, approximate age, approximate weight and height, and other\nidentifying features.\n (c) Other service. Where service is made pursuant to subdivision four\nof section three hundred eight of this chapter, proof of service shall\nalso specify the dates, addresses and the times of attempted service\npursuant to subdivisions one, two or three of such section.\n (d) Form. Proof of service shall be in the form of a certificate if\nthe service is made by a sheriff or other authorized public officer, in\nthe form of an affidavit if made by any other person, or in the form of\na signed acknowledgement of receipt of a summons and complaint, or\nsummons and notice or notice of petition as provided for in section\n312-a of this article.\n (e) Admission of service. A writing admitting service by the person to\nbe served is adequate proof of service.\n