optional
optional — Optional information.
Synopsis
- Zero or more of:
- text
phrase(db._phrase)replaceable- Graphic inlines
![[-]](figs/web/nav/down.gif)
- Indexing inlines
- Linking inlines
- Ubiquitous inlines
altanchorannotationbibliorefindexterm(db.indexterm.endofrange)indexterm(db.indexterm.singular)indexterm(db.indexterm.startofrange)inlinemediaobjectlinkolinkremarksubscriptsuperscriptxref
Attributes
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.
Parents ![[+]](figs/web/nav/right.gif)
This element occurs in 51 elements.
Children
This element contains 16 elements.
See Also
computeroutput, constant, literal, markup, option, parameter, prompt, replaceable, tag, userinput, varname
Examples
1 <article xmlns='http://docbook.org/ns/docbook'> 2 <title>Example optional</title> 4 <synopsis> ls <option>-abcCdfFgilLmnopqrRstux1</option> 6 <optional>names</optional> </synopsis> 8 </article>
1
2 ls -abcCdfFgilLmnopqrRstux1
names