HTML entities

[Christoph Päper]

Marius Spix via Unicode <unicode at unicode.org>:
> 
> CSS is also no solution, because <sub> and <sub> are semantic tags (like <del>, <strong>, <em> and <kbd>) and not just stylistic ones (like <s>, <b>, <i> or <tt>).

When HTML introduced the `b`/`strong` and `i`/`em` distinctions, it should also have added presentational/semantic pairs 

- `sup`/`exp` (exponent) or `pow` (power) and 
- `sub`/`idx`, `ind` (index) or `base`. 

I don’t think the WHATWG or W3C would be interested in adding them now.