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DocBook 5: The Definitive Guide by Richard L. Hamilton, Norman Walsh

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Name

optional — Optional information

Synopsis

optional ::= (text | phrase db._phrase | replaceable | Graphic inlines | Indexing inlines | Linking inlines | Ubiquitous inlines)*

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 being documented.

Processing expectations

Formatted inline.

Optional arguments in a synopsis are usually given special typographic treatment, and 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.

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>

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