optional
optional — Optional information.
Synopsis
optional ::= ![[-]](figs/web/nav/down.gif)
![[+]](figs/web/nav/right.gif)
- Zero or more of:
- text
- Graphic inlines
- Indexing inlines
- Linking inlines
- Ubiquitous inlines
abbrevacronymaltanchorbibliorefcorefdateemphasis(db._emphasis)firstterm(db._firstterm)footnotefootnoterefforeignphrase(db._foreignphrase)glossterm(db._glossterm)indexterm(db.indexterm.endofrange)indexterm(db.indexterm.singular)indexterm(db.indexterm.startofrange)inlinemediaobjectlinkolinkphrase(db._phrase)quote(db._quote)remarksubscriptsuperscripttrademarkwordaswordxref
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.
Parents
These elements contain optional: bridgehead, citation, citetitle, emphasis (db.emphasis), entry, firstterm (db.firstterm), glosssee, glossseealso, glossterm (db.glossterm), line, link, literallayout, member, olink, orgdiv, para, phrase (db.phrase), primary, quote (db.quote), remark, secondary, see, seealso, simpara, subtitle, term, termdef, tertiary, title, titleabbrev.
Children
The following elements occur in optional: text, abbrev, acronym, alt, anchor, biblioref, coref, date, emphasis (db._emphasis), firstterm (db._firstterm), footnote, footnoteref, foreignphrase (db._foreignphrase), glossterm (db._glossterm), indexterm (db.indexterm.endofrange), indexterm (db.indexterm.singular), indexterm (db.indexterm.startofrange), inlinemediaobject, link, olink, phrase (db._phrase), quote (db._quote), remark, subscript, superscript, trademark, wordasword, 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