55 ILCS 5/3-11003
For the purpose of establishing a control over the withdrawal, in accordance with the provisions of this Division, of all county moneys deposited in any bank, savings and loan association, savings bank, or credit union, as hereinafter required, such moneys are hereby classified as follows:
Class A. All taxes and special assessments received by the county treasurer in his capacity as ex officio county collector or ex officio town collector, and held by him pending distribution to the several governments or authorities entitled to receive the same, shall be known as "Class A" funds.
Class B. All other moneys belonging to the State of Illinois or to any political or corporate subdivision thereof, except the county, shall be known as "Class B" funds.
Class C. All moneys belonging to the county in its corporate capacity shall be known as "Class C" funds.
Class D. All other county moneys as defined in Section 3-11001 shall be known as "Class D" funds.
55 ILCS 5/3-11003