For good cause shown, the Board may permit any interested 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 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 the peititioner would make.
[49 FR 10637, Mar. 21, 1984, as amended at 86 FR 1780, Jan. 11, 2021]