The <sub> Tag in HTML 5

The <sub> tag creates subscript text. The sub element is one of the phrase elements in HTML. The content of the sub element is displayed below the normal baseline level. The <sup> tag performs a similar function except that the content is displayed above the normal baseline level.

An alternative to the <sub> tag is the vertical-align: sub CSS style property. The vertical-align: super style raises the applicable content above the normal baseline level.