The following persons may appear in a representative capacity at a hearing:

(1) An individual representing themself;

(2) An attorney at law duly qualified and entitled to practice before the supreme court of the state of Washington;

(3) A legal intern admitted to limited practice under Rule 9 of the Washington state supreme court's admission and practice rules. No legal intern, however, may appear without the presence of a supervising lawyer unless the administrative law judge approves the intern's sole appearance in advance; and

(4) A bona fide officer, partner, or owner of a business, association, partnership, or corporation who appears on behalf of such business, association, partnership, or corporation.