Lower small characters for formulas and footnotes.
Unicode has subscripts for digits and a short list of letters: a e h i j k l m n o p r s t u v x.
ₕ₂ₒ ₐₙd ₓ₂
H₂O and x₂
Unicode includes subscript digits, plus and minus signs, brackets and a limited set of letters. The tool converts those it knows and leaves the rest untouched. Digits are enough for chemical formulas such as H₂O and CO₂.
The digits only variant converts numbers and leaves letters alone, which suits formulas written in normal letters.
No. These are Unicode characters that happen to look like styled letters, so they paste into any app that accepts text, with no font installation. Because they are different characters from normal letters, search and screen readers may handle them differently.
a, e, h, i, j, k, l, m, n, o, p, r, s, t, u, v and x. Others do not exist in Unicode.
No. HTML tags change the display of text on web pages. These are separate characters that paste into plain text.