A brief of an amicus curiae may be filed only with the written
consent of all parties, or by leave of the administrative law judge
granted upon motion, or on the request of the administrative law judge,
except that consent or leave shall not be required when the brief is
presented by an officer of an agency of the United States, or by a
state, territory or commonwealth. The amicus curiae shall not
participate in any way in the conduct of the hearing, including the
presentation of evidence and the examination of witnesses.
