Superscript and Subscript
You can add superscripts to text to write things like H2O and E=mc2. Here's how:
Subscript:
H<sub>2</sub>O
Superscript:
E=mc<sup>2</sup>
Superscripts are often used when creating links to footnotes at the bottom of a page. In printed documents, it is common practice to have a number as the reference to the footnote, like this:
Footnotes in printed documents:
There is a reference to a footnote at the end of this sentence1.
On web pages, it is common practice to make the footnote references clickable, so that you can jump down to the bottom of the page to read the footnote. Some authors use the same conventions that they would use in printed documents, meaning that they use a number. On the web, though, it's usually better to provide a larger target to click on than a single small number. Some people with disabilities (and many people without disabilities) will have a hard time clicking on such a small link.
Links to footnotes on the web
(Note: these links don't actually go anywhere. They're just examples.)
Link too small: There is a reference to a footnote at the end of this sentence1.
A better method: There is a reference to a footnote at the end of this sentence[1].
Another good method: There is a reference to a footnote at the end of this sentence[note 1].
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