New York Civil Practice Law and Rules
§ 306. Proof of Service/Affidavit of service.
(a) Generally. Proof of service/Affidavit of Service shall specify the papers served, the person who was served and the date, time, address, or, in the event there is no address, place and manner of service, and set forth facts showing that the service was made by an authorized person and in an authorized manner.
(b) Personal service. Whenever service is made pursuant to this article by delivery of the summons to an individual, proof of service shall also include, in addition to any other requirement, a description of the person to whom it was so delivered, including, but not limited to, sex, color of skin, hair color, approximate age, approximate weight and height, and other identifying features.
(c) Other service. Where service is made pursuant to subdivision four of section three hundred eight of this chapter, proof of service/affidavit of service shall also specify the dates, addresses and the times of attempted service pursuant to subdivisions one, two or three of such section.
(d) Form. Proof of service/Affidavit of service shall be in the form of a certificate if the service is made by a sheriff or other authorized public officer, in the form of an affidavit if made by any other person, or in the form of a signed acknowledgement of receipt of a summons and complaint, or summons and notice or notice of petition as provided for in section 312-a of this article.
(e) Admission of service. A writing admitting service by the person to be served is adequate proof of service/affidavit of service.