An applicant for review or further review may designate any of the following persons as his or her agent in addition to a legal representative:
1. The spouse, a lineal ancestor or descendant, or a sibling of the applicant;
2. An executive officer or employee, if the applicant is a corporation;
3. An attorney-at-law or certified labor consultant;
4. Any other person who has been permitted by the Board or Review prescribed in Article 99 to represent the applicant.