HTML Acronyms, Abbreviations and Definitions Tutorial


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HTML Tags for Acronyms, Abbreviations and Definitions

(Some links on this page take you to details in the HTML Tag Reference. Bookmark this page in your Favorites so you can come back to it later.)

The tags for including definitions, abbreviations and acronyms in HTML 5 include:

For the meanings of HTML vocabulary terms, see Definitions of HTML Terminology.

Combining the <abbr> tag with the <dfn> tag

Using the <dfn> tag with <abbr> to define an acronym or abbreviation

The value of the title attribute of the <dfn> tag should always be the term that is being defined. When an acronym or abbreviation is associated with a definition, it could be either the abbreviated form or its expanded meaning that is being defined. Whether the acronym or its expansion appears in the <dfn> tag's title attribute, which identifies the specific term being defined, depends on whether it's the abbreviated form or its expanded meaning that is being defined.

Defining a term that is abbreviated

An <abbr>'s direct parent <dfn> tag will also assume the value of the <abbr>'s title attribute. When an abbreviation is a short form of the actual term being defined, the title attribute should be the full expanded acronym meaning, not the acronym or abbreviation that stands for the subject of the definition. Since this is the same purpose that the title attribute of the <abbr> tag serves, the title can simply be coded there:

<dfn><abbr title="Internet Corporation for Assigned Names and Numbers">ICANN</abbr></dfn>
is the international organization which helps ensure that
Internet domain names are assigned in an orderly manner.
Defining the acronym or abbreviation itself

When an acronym's meaning is being clarified by expanding it, then it is the acronym itself that is being defined and the title attribute of the parent <dfn> tag also needs to be coded to indicate it is not the expanded meaning in the <abbr> tag's title but the acronym or abbreviation itself that is being defined:

When we use the acronym
<dfn title="RSS"><abbr title="Really Simple Syndication">RSS</abbr></dfn>
it is the abbreviation for <b>Really Simple Syndication</b>, not RDF Site Summary.

There are some good examples of defining acronyms in HTML on the site.

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