(a) Closing the record. The record will be closed on a date announced by the Board by written notice.

(b) Supplementing the record after the record is closed. Except as the Board may otherwise order in its discretion, no evidence shall be received after the record is closed. However, at any time after the closing of the record and prior to a decision of the appeal by the Board, at the request of a party or upon its own initiative, the Board may reopen the record for the purpose of receiving newly discovered evidence or for such other reason as may appear to the Board to be appropriate.