5 ILCS 100/5-35

(a) Before the adoption, amendment, or repeal of any rule, each agency shall accomplish the actions required by Section 5-40, 5-45, or 5-50, whichever is applicable. (b) No action by any agency to adopt, amend, or repeal a rule after this Act has become applicable to the agency shall be valid unless taken in compliance with this Section. A proceeding to contest any rule on the ground of non-compliance with the procedural requirements of this Section must be commenced within 2 years from the effective date of the rule. (c) The rulemaking procedures of this Article 5 do not apply to a matter relating solely to agency management or personnel practices or to public property, loans, or contracts.