Ill. Admin. Code tit. 20, § 1790.210
a) A party may be represented by an attorney who is licensed in Illinois or by an attorney otherwise permitted by law to practice in the State. Attorneys who appear in a representative capacity must file a written notice of appearance setting forth:
2) The name, address and email address of the party represented; and
b) An attorney may withdraw upon written notice to the ALJ.
e) Any party may appear on his or her own behalf.
2) Substitution of written argument in place of oral argument; or