N.Y.C. Admin. Code § 11-350: § 11-350 Affidavits of publication and mailing of necessary notices to be preserved.

It shall be the duty of the commissioner of finance or his or her designee to procure, preserve and register at the department of finance, affidavits of the publication and mailing of all the advertisements and notices by this chapter required to be published and mailed, and such affidavits shall be presumptive proof of such publication and mailing in all the courts of this state.