N.Y. SCT Law § 40-D

§ 40-d. Abandonment of claim of title under tax deeds on cancellation\nof sale. Before the county treasurer shall cancel a tax sale, pursuant\nto the provisions of this article, and issue a certificate of\ncancellation, the party claiming under the tax deed issued from the sale\nsought to be cancelled, his heirs or assigns, shall deliver to the\ncounty treasurer an instrument of abandonment of any and all claims and\ninterest under and by virtue of such tax deed duly executed and\nacknowledged in the same manner as a deed, which shall not affect his\nright to a refund, together with satisfactory proof that he has not\nconveyed the land described in such tax deed or any part thereof or\ninterest therein. At the time of issuing the certificate of cancellation\nthe county treasurer shall transmit such instrument of abandonment to\nthe county clerk. The county clerk shall record such instrument of\nabandonment in a book of deeds in his office and index the same as\nthough the party executing it were a grantor in a deed.\n This section shall not apply to any cancellation of a tax sale and\nissuance of a certificate of cancellation thereof made on application of\none other than the purchaser, his heirs or assigns.\n