92 Ill. Adm. Code 450.150
Appearances
Section 450
Section 450.150 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 by an
attorney at law licensed to practice in the State of Illinois, or both;
b) A business, non-profit or governmental organization may appear
by any officer, employee, or representative, or may be represented by an
attorney licensed to practice in the State of Illinois, or both;
c) Any attorney appearing in a representative capacity shall file
a written notice of appearance.