... a footnote.

I am indebted for this phrase to the 9,000-odd writers who have used it before me.

—Gilbert Sorrentino, Imaginative Qualities of Actual Things, p. 240, footnote. The phrase is "he looks at her as if seeing her for the first time." (And then "the scene mercifully fades before my eyes." Two asterisks leading to the same footnote!)