Footnote

A footnote was a short note on the bottom of a page with additional information about the subject.

In 2155, John Frederick Paxton worried that it would only be a matter of time before rampant cross-breeding between Humans and aliens rendered the term "Human" worthy only of a footnote in a medical text. (ENT: "Terra Prime")

In 2375, The Doctor sarcastically commented that a paper Crell Moset intended to write should contain a footnote as to where had honed his surgical skills which read, "For further details, see Cardassian death camps." (VOY: "Nothing Human")