Add grouping commas

Warning²Federal courts, Illinois courts21st and 22nd editions

A number of four or more digits is grouped into threes with commas, the same in prose and in citations; a locator's own numbering system carries none.¹

1. 1R. 6.2(a)(vii) Numerals.
2. 2A warning: the form is usually wrong under the rule in note 1, and context can justify it.