Hold on a minute! Isn’t this a
typographical convention, and presentational by definition? Isn’t presentation the realm of CSS? Why, yes, it is!
sup are the most heinous interlopers of all tags in the HTML5 spec. Treat them with disdain. They are the Midichlorians of Markup.
sup, sit somewhat awkwardly in the HTML5 spec. Once regarded as evil, evil
presentational tags (presentation being something CSS, not HTML, should be used for), HTML5 redefines them as something else. Something slightly less evil. But still, arguably, evil.
Some of the redefinitions of these tags are round pegs smashed through square holes and are tenuous to say the least. Just be careful. In almost every single situation,
will not only suffice, they will be significantly more appropriate and, additionally, they will be interpreted by assistive technologies more accurately.
For the love of everything pleasant on the planet, don’t use
sup just to shift the vertical placement of text on a line willy-nilly. The CSS property
(along with numerous other CSS methods) will achieve a much more respectable result.
Global attributes Example
<p>A blind <u>loin</u> (<i>Panthera leo</i>) asked what the 2 in E=MC
<sup>2 </sup> and H<sub>2</sub>O meant.</p>
<p>She went on to ask if it was supposed to be <b>emphasized</b> in some way.</p>
<p>She reached the conclusion that this HTML is, in fact, <s>presentational, rather than</s> meaningful.</p>
<p>Disclaimer: <small>Most of this page, on most levels, it mostly nonsense.</small></p>