621—2.6 (20) Appearances and conduct of parties. Any party may appear and be heard on its own behalf, or by its designated representative. Designated representatives shall file a notice of appearance with the board for each case in which they appear for a party. Filing of pleadings on behalf of a party shall be equivalent to filing a notice of appearance. All persons appearing in proceedings before the board shall conform to the standard of ethical conduct required of attorneys before the courts of the state of Iowa. If any person refuses to conform to such standards, the board may decline to permit such person to appear in any proceeding.