21.43—Comments by other parties.
(a)
Any party to a proceeding, other than an applicant or the Department's counsel, may file comments on—
(3)
Both, if the comments are filed within the time period specified in paragraphs (a)(1) and (a)(2) of this section.
(b)
The commenting party may not participate further in proceedings on the application unless the adjudicative officer determines that further participation is necessary to permit full exploration of matters raised in the comments.