optional

optional — Optional information

Synopsis

optional ::= [-]

Description

The optional element indicates that a specified argument, option, or other text is optional. The precise meaning of “optional” varies according to the application or process begin documented.

Processing expectations

Formatted inline.

Optional arguments in a synopsis are usually given special typographic treatment, often they are surrounded by square brackets. The optional tag is expected to generate the brackets.

Outside a synopsis, the typographic treatment of optional is application-specific.

Children

The following elements occur in optional: text, alt, anchor, annotation, biblioref, indexterm (db.indexterm.endofrange), indexterm (db.indexterm.singular), indexterm (db.indexterm.startofrange), inlinemediaobject, link, olink, phrase (db._phrase), remark, replaceable, subscript, superscript, xref.

See Also

computeroutput, constant, literal, markup, option, parameter, prompt, replaceable, tag, userinput, varname

Examples

<article xmlns='http://docbook.org/ns/docbook'>
<title>Example optional</title>

<synopsis>
ls <option>-abcCdfFgilLmnopqrRstux1</option>
   <optional>names</optional>
</synopsis>

</article>
ls -abcCdfFgilLmnopqrRstux1
   [names]

ChangeLog

This alpha reference page is $Revision: 7120 $ published Sun, 22 Jul 2007.