Add the interviewee's name or the date

Warning²Federal courts, Illinois courts21st and 22nd editions

An interview is cited by the person interviewed and by the date it took place; both are facts about the interview itself rather than anything the citation can supply.¹

1. 1R. 17.2.5 Interviews. Tables: R. 17.2 Unpublished Materials.
2. 2A warning: the form is usually wrong under the rule in note 1, and context can justify it.