Capitalize “Id.” only at a sentence head

Error²Federal courts, Illinois courts21st and 22nd editions

“Id.” takes a capital at the head of a citation sentence and stays lowercase behind a signal, behind a semicolon, or inside a citation clause.¹

1. 1R. 1.1(b)(i) Citation sentences; B1.1 Citation Sentences and Clauses; R. 1.1(b)(ii) Citation clauses. Tables: R. 4.1 “Id.”; B10.2 Short Form Citation.
2. 2An error: the rule in note 1 allows one form, and this is not it.