Style Manual: Illinois Administrative Code and Illinois Register
The Illinois Administrative Code is the result of the Illinois Administrative Procedure Act (IAPA) as amended by (5 ILCS 100/). The Act requires the Secretary of State to develop a codification system for the administrative rules of state agencies. A plan for codification was adopted by the Secretary of State as a set of rules in July of 1998 (22 Ill. Reg. 11532, effective July 1, 1998).