Use the author's full name

Warning²Federal courts, Illinois courts, Law reviews21st and 22nd editions

A “supra” short form uses the author's last name only when the author is a person; an institution keeps its full name, because the last word alone does not identify it.¹

1. 1R. 4.2(a) “Supra.”. Tables: B15.2 Short Form Citation.
2. 2A warning: the form is usually wrong under the rule in note 1, and context can justify it.