A shortened form of a word or phrase used chiefly in writing to represent the complete form, such as Mass. for Massachusetts or USMC for United States Marine Corps (e.g., WWW, HTTP, URI, Mass., etc.).
<abbr title="World Wide Web">WWW</abbr>
A word formed from the initial letters of a name, such as WAC for Women's Army Corps, or by combining initial letters or parts of a series of words, such as radar for radio detecting and ranging (e.g., WAC, radar, etc.).
<acronym title="Women's Army Corps">WAC</acronym>
A statement of the meaning of a word, phrase, or term, as in a dictionary entry. The DFN element can be used to mark up the defining instance of a term. In an article, the DFN can be used the first time we mention something and explain what it means. DFN indicates that this is the defining instance of the enclosed term.
<dfn title="Open grassy plains with minimal trees">Rangelands</dfn>
Cite is an element and an attribute. As an element, it can be used to cite other references, such as book titles, people, movie titles etc. As an attribute, cite can be used with blockquote and q to provide further meaning
<cite>Designing with Web Standards</cite> is a book by Jeffrey Zeldman.
<blockquote cite="http://www.mycom.com/tolkien/twotowers.html">
<p>They went in single file, running like hounds on a strong scent, and an eager light was in their eyes. </p>
</blockquote>