Use the correct supplement form

Error²Federal courts, Illinois courts21st and 22nd editions

A supplement citation abbreviates the word as “Supp.” and joins the main volume to it with an ampersand, never a comma or “and”.¹

1. 1R. 3.1(c) Supplements. Tables: R. 12.2.2 Exceptions; R. 12.2 Choosing the Proper Citation Form.
2. 2An error: the rule in note 1 allows one form, and this is not it.