2. Carat character is used to indicate subscript in this text version.
"The History of Antiquity, Vol. II (of VI)"
Max Duncker
Underscores before bracketed numbers in equations denote a subscript.
"The Chemistry, Properties and Tests of Precious Stones"
John Mastin
We already know how to represent each of the three Propositions of a Syllogism in subscript form.
"Symbolic Logic"
Lewis Carroll