DL - Definition Lists

A definition list is a list of terms and corresponding definitions. Definition lists are typically formatted with the term on the left with the definition following on the right or on the next line. The definition text is typically indented with respect to the term.

An alternative format places the term left aligned in a wide margin and the definition on one or more lines to the right of the term. If the DT term does not fit in the DT column (one third of the display area), it may be extended across the page with the DD section moved to the next line, or it may be wrapped onto successive lines of the left hand column.

The opening list tag must be <DL>. It is followed by an optional list header (<LH>caption</LH>) and then by term names (<DT>) and definitions (<DD>). For example:

<DL>
<LH>List Header</LH>
<DT>Term 1<dd>This is the definition of the first term.
<DT>Term 2<dd>This is the definition of the second term.
</DL>

which could be rendered as:

List Header

Term 1

This is the definition of the first term.

Term 2

This is the definition of the second term.

The definition list element can take the COMPACT attribute, which suggests that a compact rendering be used, and is appropriate if the list elements are small and/or the entire list is large.

Note: Use the NOTE element when you want to have an indented note. The practice of using <DD> elements without corresponding <DT> elements is deprecated.

Permitted Attributes for the DL Element

ID

An SGML identifier used as the target for hypertext links or for naming particular elements in associated style sheets. Identifiers are NAME tokens and must be unique within the scope of the current document.

LANG

This is one of the ISO standard language abbreviations, e.g. "en.uk" for the variation of English spoken in the United Kingdom. It can be used by parsers to select language specific choices for quotation marks, ligatures and hypenation rules etc. The language attribute is composed from the two letter language code from ISO 639, optionally followed by a period and a two letter country code from ISO 3166.

CLASS

This a space separated list of SGML NAME tokens and is used to subclass tag names. By convention, the class names are interpreted hierarchically, with the most general class on the left and the most specific on the right, where classes are separated by a period. The CLASS attribute is most commonly used to attach a different style to some element, but it is recommended that where practical class names should be picked on the basis of the element's semantics, as this will permit other uses, such as restricting search through documents by matching on element class names. The conventions for choosing class names are outside the scope of this specification.

CLEAR

This attribute is common to all block-like elements. When text flows around a figure or table in the margin, you sometimes want to start an element like a header, paragraph or list below the figure rather than alongside it. The CLEAR attribute allows you to move down unconditionally:

clear=left

move down until left margin is clear

clear=right

move down until right margin is clear

clear=all

move down until both margins are clear

Alternatively, you can decide to place the element alongside the figure just so long as there is enough room. The minimum width needed is specified as:

clear="40 en"

move down until there is at least 40 en units free

clear="100 pixels"

move down until there is at least 100 pixels free

The style sheet (or browser defaults) may provide default minimum widths for each class of block-like elements.

COMPACT

The presence of this attribute indicates the user agent should use reduced interitem spacing. The COMPACT attribute may also reduce the width of the left-hand (DT) column.

In practice, there are several ways to increase the compactness of lists: reduced vertical interitem spacing, smaller font size, or even to avoid line breaks between items. This is best handled through associated style sheets and the class attribute.

The opening list tag must be DL COMPACT. It must be immediately followed by the first term (DT). For example:

<DL compact>
<DT>Term<DD>This is the first definition in compact format.
<DT>Term<DD>This is the second definition in compact format.
</DL>