35 Ill. Adm. Code 105.602
Parties
Section 105.602Â Parties
a)        Petitioner. The
person who files a petition for review of the Agency's final decision must be
named the petitioner.
b)        Respondent. The
Agency must be named the respondent. If a petition is filed under Section 105.604(c)
by a person other than the permit applicant, the permit applicant must be named
as a respondent in addition to the Agency.