For good cause shown, the Board may permit any interested person or
party to intervene or otherwise participate in any proceeding held by
the Board. Except when requested orally before the Board, a petition to
intervene or otherwise participate shall be in writing (original and
four copies) and shall state with precision and particularity: (a) The
petitioner's relationship to the matters involved in the proceedings,
and (b) the nature of the presentation which he would make. Copies of
the petition shall be served to all parties or interested persons known
to participate in the proceeding, who may respond to the petition.
Appropriate service shall be made of any response.
