N.Y. Comp. Codes R. & Regs. tit. 20 § 484.9
Tax Law, § 514
Except in accordance with proper judicial order or as otherwise provided by law, it is unlawful for the Tax Commission, any tax commissioner, any officer or employee of the Department of Taxation and Finance or any person who, pursuant to article 21 of the Tax Law, is permitted to inspect any return, or to whom any information contained in any return is furnished, or any person engaged or retained by the department on an independent contract basis, or any person who in any manner may acquire knowledge of the contents of a return or report, to divulge or make known in any manner any information relating to the business of a carrier or any particulars set forth or disclosed in any return under article 21 of the Tax Law. The officers charged with the custody of such return are not required to produce any of them or evidence of anything contained therein in any action or proceeding in any court, except on behalf of the State of New York, the State Tax Commission, the Department of Taxation and Finance or the Department of Transportation in an action or proceeding under the provisions of the Tax Law, the Vehicle and Traffic Law or the Transportation Law, or on behalf of any party to any action or proceeding under the provisions of said article 21, the Vehicle and Traffic Law or the Transportation Law when the returns or facts shown thereby are directly involved in such action or proceeding, in any of which events the court may require the production of, and may admit in evidence so much of said returns or of the facts shown thereby as are pertinent to the action or proceeding, and no more.
N.Y. Comp. Codes R. & Regs. Tit. 20 § 484.9