Upon the filing of an appeal to the Board from a decision of a hearings officer, the Secretary to the Board shall notify all parties to the decision of the hearings officer that an appeal has been filed. The parties shall not have the right to submit additional evidence, except that:

(a) The Board may permit the submission of additional evidence upon a showing by a party that he or she has additional evidence to present which, for valid reasons, he or she was unable to present at an earlier stage;

(b) The Board may request the submission of additional evidence; and

(c) The Board may designate any employee of the Board to take additional evidence and to report his or her findings to the Board. Any such additional evidence shall be submitted in such manner as the Board may indicate and shall be included in the record.

(d) Any party may submit additional argument in writing with the appeal to the Board. No party shall have the right to an oral presentation before the Board except where the Board so permits. Such presentation may be limited in form, subject matter, length, and time as the Board may indicate to the parties.