optional — Optional information


Content Model

optional ::=


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.


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


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

ls <option>-abcCdfFgilLmnopqrRstux1</option>

ls -abcCdfFgilLmnopqrRstux1


This alpha reference page is $Revision: 1.4 $ published $Date: 2005/10/31 12:31:55 $.