N.Y. Comp. Codes R. & Regs. tit. 12, § 65.51 – Failure to appear.

(a) Subject to the provisions of subdivisions (c) and (d) of this section, the failure of a party to appear at a hearing is a waiver of all rights except the right to be served with a copy of the decision of the board and to request board review pursuant to section 65.60 of this Part.
(b) Request for reinstatement must be made, in the absence of extraordinary or unusual circumstances, within five days after the scheduled hearing.
(c) The board, upon a showing of good cause, may excuse a party’s failure to appear and reopen the hearing.
(d) The board may require a party to pay reasonable costs incurred by the board caused by a party’s failure to appear as a condition for reopening a hearing.