Take your icon game to the next level. Check out Fonticons, from the maker of Font Awesome.
             

fa-subscript · Unicode: f12c · Created: v3.1 · Categories: Text Editor Icons

After you get up and running, you can place Font Awesome icons just about anywhere with the <i> tag:

fa-subscript
<i class="fa fa-subscript"></i>

Looking for more? Check out the examples.