Code of Federal Regulations Title 29. Labor § 29.7.12 Intervention;  other participation

(a) 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 and shall state with precision and particularity:

(b) 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.