(1) No person may appear in a representative capacity before the commission or the director of his or her designated administrative law judge other than the following:

(a) Attorneys at law duly qualified and entitled to practice before the supreme court of the state of Washington.

(b) Attorneys at law qualified and entitled to practice before the highest court of record of any other state, if the attorneys at law of the state of Washington are permitted to appear in a representative capacity before administrative agencies of such other state, and if not otherwise prohibited by Washington state law.

(c) A bona fide officer, authorized manager, partner, or full time employee of an individual firm, association, partnership, or corporation who appears for such individual firm, association, partnership or corporation.

(d) Such other persons as may be permitted by the commission or director upon a showing by a party to the hearing of such a necessity or such a hardship as would make it unduly burdensome upon him to have a representative as set forth under subsections (a), (b) and (c) above.

(2) Nothing herein shall preclude an individual from appearing on his own behalf, pro se.