N.Y. Real Property Law § 389: Any person interested may appear and defend

§ 389. Any person interested may appear and defend. Any person

interested in the property, or whose interests may be affected by the

final order or judgment of registration in the proceeding, whether

specifically named in the notice or not, may enter his appearance by

serving a copy of the same on the registrar of the county in which the

property is located and with the clerk of the supreme court in such

county, and filing the original thereof together with proof of service

with the county clerk on or before the return day or within such further

time as may be allowed by the court; and may enter his objections, if

any, by likewise serving a copy of the same on the registrar of the

county in which the property is located and with the clerk of the

supreme court in such county, and filing the original thereof together

with proof of service with the county clerk on or before the return day

or within such further time as may be allowed by the court; and may

oppose the petition for registration of the property as belonging to the

petitioner, or set up a cross-demand to have the title registered in his

own behalf. In any case, he shall state particularly what his interest

is and shall specifically state all objections to the petition.