Replace the numeral with a word

Warning²Federal courts, Illinois courts21st and 22nd editions

“Twenty-four defendants were named”, not “24 defendants were named” — a sentence does not open with a numeral.¹

1. 1R. 6.2(a)(i) Numerals; R. 6.2(c) Section (§) and paragraph (¶) symbols.
2. 2A warning: the form is usually wrong under the rule in note 1, and context can justify it.