Each attorney appearing in a criminal action is required to file a written notice of appearance on or before the time of the attorney's first appearance in court or not later than 10 days after appointment or retainer, whichever is sooner. The notice shall contain the attorney's name, office address and telephone number, the name of the person on whose behalf he or she is appearing, and the identification number of the accusatory instrument or instruments by which such person is charged.
N.Y. Comp. Codes R. & Regs. Tit. 22 § 200.5