92 Ill. Adm. Code 454.70
Appearances
Section 454
Section 454.70 Appearances
Any person either involved in or
entitled to participate in proceedings may appear as follows:
a) A natural person may appear in his own behalf or through
counsel of his choice;
b) A business, non-profit or governmental organization may appear
by an officer, employee or representative, or may be represented by counsel of
its choice;
c) Any attorney appearing in a representative capacity shall file
a written notice of appearance.