Iota Subscript

A poem by Robert Lee Frost

Seek not in me the big I capital,
Not yet the little dotted in me seek.
If I have in me any I at all,
'Tis the iota subscript of the Greek.

So small am I as an attention beggar.
The letter you will find me subscript to
Is neither alpha, eta, nor omega,
But upsilon which is the Greek for you.