Acronym

The HTML   element has been deprecated since HTML5 in favor of the  element. It allowed authors to clearly indicate a sequence of characters that compose an acronym or abbreviation for a word. It renders a dotted underline beneath the selected text. The user must hover their cursor over the selected text in order to view the acronym.

Attributes
See Global HTML Attributes.
 * Global Attributes

It is best to associate the global  attribute to this element in order to indicate the text to be shown for the acronym.

HTML example:

Rendering
Acronyms are typically rendered identically to elements, with a dotted line below them.