HTML sub element

The <sub> HTML element specifies inline text which should be displayed as subscript for solely typographical reasons. Subscripts are typically rendered with a lowered baseline using smaller text.

The <sub> element should be used only for typographical reasons—that is, to change the position of the text to comply with typographical conventions or standards, rather than solely for presentation or appearance purposes.

For example, using <sub> to style the name of a company which uses altered baselines in their wordmark would not be appropriate; instead, CSS should be used. For example, you could use the vertical-align property with a declaration like vertical-align: sub or, to more precisely control the baseline shift, vertical-align: -25%.