Each attorney appearing in a proceeding is required to file a written notice of appearance on or before the time of the attorney's first appearance in court or no later than 10 days after appointment or retainer, whichever is sooner. The notice shall contain the attorney's name, office address and telephone number, and the name of the person on whose behalf he or she is appearing.
N.Y. Comp. Codes R. & Regs. Tit. 22 § 205.10