Use the official reporter

Warning²Federal courts, Illinois courts21st and 22nd editions

Illinois assigned public-domain citations to opinions filed on or after July 1, 2011; an opinion already in the Official Reports before then is cited to the print reporter.¹

1. 1Ill. S. Ct. R. 6; Ill. S. Ct. R. 341(g); R. 10.3.3 Public Domain Format; T1.3 States and the District of Columbia.
2. 2A warning: the form is usually wrong under the rule in note 1, and context can justify it.