revision:
The <dfn> HTML element is used to indicate the term being defined within the context of a definition phrase or sentence. The <p> element, the <dt>/<dd> pairing, or the <section> element, which is the nearest ancestor of the <dfn>, is considered to be the definition of the term.
The <dfn> tag stands for the "definition element", and it specifies a term that is going to be defined within the content. The nearest parent of the <dfn> tag must also contain the definition/explanation for the term.
The term inside the <dfn> tag can be any of the following:
1. just as the content of the <dfn> element,
2. or, with the "title" attribute added,
3. or, with an <abbr> tag inside the <dfn> element,
4. or, with the "id" attribute added. Then, whenever a term is used, it can refer back to the definition with an <a> tag.
<dfn> . . . . </dfn>
A validator is a program that checks for syntax errors in code or documents.
code:
<p class="spec">A <dfn id="def-validator">validator</dfn> is a program
that checks for syntax errors in code or documents.</p>
HTML is the standard markup language for creating web pages.
HTML is the standard markup language for creating web pages.
HTML is the standard markup language for creating web pages.
HTML is the standard markup language for creating web pages.
This is some text...
This is some text...
Learn HTML now.
code:
<div class="spec">
<p class="spec"><dfn>HTML</dfn> is the standard markup language
for creating web pages.</p>
<p class="spec"><dfn title="HyperText Markup Language">HTML</dfn>
is the standard markup language for creating web pages.</p>
<p class="spec"><dfn><abbr title="HyperText Markup Language">
HTML</abbr></dfn> is the standard markup language for creating web pages.</p>
<p class="spec"><dfn id="html-def">HTML</dfn> is the standard markup
language for creating web pages.</p>
<p class="spec">This is some text...</p>
<p class="spec">This is some text...</p>
<p class="spec">Learn <a href="#html-def">HTML</a> now.</p>
</div>