| DocBook: The Definitive Guide 2.0.12 (Alpha)

# ulink

$Revision: 1.4 $

$Date: 2004/05/19 15:56:44 $

ulink — A link that addresses its target by means of a URL (Uniform Resource Locator)

## Synopsis

### Mixed Content Model

    ulink ::=
    (#PCDATA|footnoteref|xref|biblioref|abbrev|acronym|citation|
     citerefentry|citetitle|emphasis|firstterm|foreignphrase|
     glossterm|footnote|phrase|orgname|quote|trademark|wordasword|
     personname|link|olink|ulink|action|application|classname|
     methodname|interfacename|exceptionname|ooclass|oointerface|
     ooexception|package|command|computeroutput|database|email|envar|
     errorcode|errorname|errortype|errortext|filename|function|
     guibutton|guiicon|guilabel|guimenu|guimenuitem|guisubmenu|
     hardware|interface|keycap|keycode|keycombo|keysym|literal|code|
     constant|markup|medialabel|menuchoice|mousebutton|option|
     optional|parameter|prompt|property|replaceable|returnvalue|
     sgmltag|structfield|structname|symbol|systemitem|uri|token|type|
     userinput|varname|nonterminal|anchor|author|authorinitials|
     corpauthor|corpcredit|modespec|othercredit|productname|
     productnumber|revhistory|remark|subscript|superscript|
     inlinegraphic|inlinemediaobject|inlineequation|synopsis|
     cmdsynopsis|funcsynopsis|classsynopsis|fieldsynopsis|
     constructorsynopsis|destructorsynopsis|methodsynopsis|indexterm|
     beginpage)*

### Attributes

Common attributes

Name | Type | Default
xrefstyle | CDATA | None
url | CDATA | Required
type | CDATA | None

## Description

The `ULink` element forms the equivalent of an HTML anchor (`<A HREF="...">`) for cross reference by a Uniform Resource Locator (URL).

### Processing expectations

Formatted inline. When rendered online, it is natural to make the content of the `ULink` element an active link. When rendered in print media, the URL might be ignored, printed after the text of the link, or printed as a footnote.

When the content of the `ULink` element is empty, i.e., for either of the following cases: `<ulink url="..."/>` and `<ulink url="..."></ulink>`, the content of the `url` attribute should be rendered as the text of the link.

Linking elements must not be nested within other linking elements (including themselves). Because DocBook is harmonizing towards XML, this restriction cannot easily be enforced by the DTD. The processing of nested linking elements is undefined.

### Future Changes

The `InterfaceDefinition` element will be discarded in DocBook V4.0. It will no longer be available in the content model of this element.

### Parents

These elements contain ulink: `abbrev`, `ackno`, `acronym`, `action`, `application`, `artpagenums`, `attribution`, `authorinitials`, `bibliocoverage`, `biblioid`, `bibliomisc`, `bibliorelation`, `bibliosource`, `bridgehead`, `citation`, `citebiblioid`, `citetitle`, `city`, `classsynopsisinfo`, `code`, `collabname`, `command`, `computeroutput`, `confdates`, `confnum`, `confsponsor`, `conftitle`, `contractnum`, `contractsponsor`, `contrib`, `corpauthor`, `corpcredit`, `corpname`, `country`, `database`, `date`, `edition`, `email`, `emphasis`, `entry`, `fax`, `figure`, `filename`, `firstname`, `firstterm`, `foreignphrase`, `funcparams`, `funcsynopsisinfo`, `function`, `glosssee`, `glossseealso`, `glossterm`, `hardware`, `holder`, `honorific`, `indexdiv`, `informalfigure`, `interfacename`, `invpartnumber`, `isbn`, `issn`, `issuenum`, `jobtitle`, `keycap`, `label`, `lineage`, `lineannotation`, `link`, `literal`, `literallayout`, `lotentry`, `manvolnum`, `member`, `modespec`, `msgaud`, `olink`, `option`, `optional`, `orgdiv`, `orgname`, `otheraddr`, `othername`, `pagenums`, `para`, `parameter`, `phone`, `phrase`, `pob`, `postcode`, `primary`, `primaryie`, `productname`, `productnumber`, `programlisting`, `property`, `pubdate`, `publishername`, `pubsnumber`, `quote`, `refentry`, `refentrytitle`, `refmiscinfo`, `refnamediv`, `refpurpose`, `releaseinfo`, `remark`, `replaceable`, `revnumber`, `revremark`, `screen`, `screeninfo`, `secondary`, `secondaryie`, `see`, `seealso`, `seealsoie`, `seeie`, `seg`, `segtitle`, `seriesvolnums`, `shortaffil`, `simpara`, `state`, `street`, `subscript`, `subtitle`, `superscript`, `surname`, `synopsis`, `systemitem`, `td`, `term`, `tertiary`, `tertiaryie`, `th`, `title`, `titleabbrev`, `tocback`, `tocentry`, `tocfront`, `trademark`, `ulink`, `userinput`, `volumenum`, `wordasword`, `year`.

### Children

The following elements occur in ulink: `abbrev`, `acronym`, `action`, `anchor`, `application`, `author`, `authorinitials`, `beginpage`, `biblioref`, `citation`, `citerefentry`, `citetitle`, `classname`, `classsynopsis`, `cmdsynopsis`, `code`, `command`, `computeroutput`, `constant`, `constructorsynopsis`, `corpauthor`, `corpcredit`, `database`, `destructorsynopsis`, `email`, `emphasis`, `envar`, `errorcode`, `errorname`, `errortext`, `errortype`, `exceptionname`, `fieldsynopsis`, `filename`, `firstterm`, `footnote`, `footnoteref`, `foreignphrase`, `funcsynopsis`, `function`, `glossterm`, `guibutton`, `guiicon`, `guilabel`, `guimenu`, `guimenuitem`, `guisubmenu`, `hardware`, `indexterm`, `inlineequation`, `inlinegraphic`, `inlinemediaobject`, `interface`, `interfacename`, `keycap`, `keycode`, `keycombo`, `keysym`, `link`, `literal`, `markup`, `medialabel`, `menuchoice`, `methodname`, `methodsynopsis`, `modespec`, `mousebutton`, `nonterminal`, `olink`, `ooclass`, `ooexception`, `oointerface`, `option`, `optional`, `orgname`, `othercredit`, `package`, `parameter`, `personname`, `phrase`, `productname`, `productnumber`, `prompt`, `property`, `quote`, `remark`, `replaceable`, `returnvalue`, `revhistory`, `sgmltag`, `structfield`, `structname`, `subscript`, `superscript`, `symbol`, `synopsis`, `systemitem`, `token`, `trademark`, `type`, `ulink`, `uri`, `userinput`, `varname`, `wordasword`, `xref`.

## Attributes

type

  `Type` is available for application-specific customization of the linking behavior.

url

  `URL` specifies the Uniform Resource Locator that is the target of the `ULink`.

## See Also

`anchor`, `link`, `olink`, `xref`.

## Examples

    <!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
              "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
    <para>
    For more information, see the O'Reilly catalog entry for
    <ulink url="http://www.ora.com/catalog/tex/"><citetitle>Making TeX
    Work</citetitle></ulink>.
    </para>

For more information, see the O'Reilly catalog entry for Making TeX Work.

For additional examples, see also `olink`, `productnumber`, `systemitem`.

type |  | uri

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