HTML dfn Tag

HTML dfn Tag: Main Tips

• The dfn tag is used to indicate a defined term.
• dfn stands for definition.
• This tag supports global attributes.

Usage of HTML Definition Tag

The HTML dfn tag represents a term that needs and has an explanation. It is usually used when a specific term first occurs in a page.

<p>
  <dfn>CSS</dfn> is the styling language for HTML.
</p>

The term definition can be provided by a <p> element, a pair of <dt> and <dd> elements, or a <section> which the <dfn> element is a child of.

Most Common Attributes

When using the HTML definition tag, you can also include a title attribute. Its value will then be considered to be the defined term, and shown when you hover your mouse over the <dfn> element:

<p>
  <dfn title="Cascading Style Sheet">CSS</dfn> is the styling language for HTML.
</p>

Note: if your dfn HTML tag has no title attribute, all it will do is specify where the defined term is in the definition.

You can also add an id attribute to the <dfn> element. Then, whenever a term is used, you can refer back to the definition using the <a> tag. This is handy when you use the same term, and want to remind the reader what it means:

<p><dfn id="css-def">CSS</dfn> is the styling language for HTML.</p>
<p>This is a paragraph</p>
<p>This is a paragraph</p>
<p>Learn <a href="#css-def">CSS</a> now.</p>

Browser support

Mobile browser support