abbr
I. Description
The abbr element is used to encapsulate an abbreviation in an HTML document. The title attribute holds the full un-abbreviated text associated with the abbreviation. When users hover over the abbreviation element the full un-abbreviated text will be displayed by the web browser to the user.
II. Examples
<!DOCTYPE html>
<html>
<head>
<title>Example Page</title>
</head>
<body>
<h1>Example HTML Page</h1>
<p>
<abbr title="Hypertext Markup Language">HTML</abbr> is
an abbreviation for 'Hypertext Markup Language'.
</p>
</body>
</html>