Technique H40:Using description lists

Applicability

HTML and XHTML

This technique relates to 3.1.3: Unusual Words (Sufficient when used with G55: Linking to definitions).

Description

The objective of this technique is to provide the description of names or terms by presenting them in a description list. The list is marked up using the dl element. Within the list, each term is put in a separate dt element, and its description goes in the dd element directly following it. Multiple terms can be associated with a single description, as can a single term with multiple descriptions, provided that semantic sequence is maintained. The title attribute can be used to provide additional information about the description list. Usage of description lists ensures that terms and their descriptions are semantically related even as presentation format changes, as well as ensuring that these terms and descriptions are semantically grouped as a unit.

Description lists are easiest to use when the descriptions are ordered alphabetically. A common use for description lists is a glossary of terms.

In HTML5 the name "Description list" was introduced. In previous versions these lists were referred to as "Definition lists".

Examples

Example 1

A list of descriptions of nautical terms used on a Website about sailing.

<dl title="Nautical terms">
  <dt>Knot</dt>
  <dd>
    <p>A <em>knot</em> is a unit of speed equaling 1 
      nautical mile per hour (1.15 miles per hour or 1.852 
      kilometers per hour).</p>
  </dd>
  <dt>Port</dt>
  <dd>
    <p><em>Port</em> is the nautical term (used on 
      boats and ships) that refers to the left side
      of a ship, as perceived by a person facing towards 
      the bow (the front of the vessel).</p>
  </dd>
  <dt>Starboard</dt>
  <dd>
    <p><em>Starboard</em> is the nautical term (used 
      on boats and ships) that refers to the right 
      side of a vessel, as perceived by a person 
      facing towards the bow (the front of the vessel).</p>
  </dd>
</dl>

Other sources

No endorsement implied.

Tests

Procedure

For any set of terms and their associated descriptions:

  1. Check that the list is contained within a dl element.
  2. Check that each term in the list being described is contained within a dt element.
  3. Check that when there is more than one term that shares the same decription that the dt elements immediately follow each other.
  4. Check that the description for each term is contained in one or more dd elements.
  5. Check that the one or more dd elements immediately follow the one or more dt elements containing the term being described.

Expected Results

  • All checks above are true.