In any proceeding before the agency, any person may appear in his or her own behalf or the person may be represented by or with an attorney or another person designated as a representative. If a person is represented by an attorney, the attorney shall be licensed to practice law by the Supreme Court of Hawaii. The agency may at any time require any person who is appearing in a representative capacity to show his or her authority to act in that capacity.
Haw. Code R. § 11-185-19