xref — A cross reference to another part of the document.


xref ::=

  • empty


Common attributes and common linking attributes.

Additional attributes:

  • endterm (IDREF)
  • xrefstyle

Required attributes are shown in bold.


The xref element forms a cross-reference from the location of the xref to the element to which it points. Unlike link and the other cross-referencing elements, xref is empty. The processing system has to generate appropriate cross-reference text for the reader.

Processing expectations

Under ordinary circumstances, the xref points to some element with its linkend attribute and the processing system generates appropriate cross-reference text. There are three ways for the author to influence the generated text:

  1. If the endterm attribute is specified on xref, the content of the element pointed to by endterm will be used as the text of the cross-reference.

  2. Otherwise, if the object pointed to has a specified xreflabel, the content of that attribute will be used as the cross-reference text.

  3. Finally, the author may specify a keyword (or other information) in the xrefstyle attribute. Unlike endterm and xreflabel which have rigid semantics, the content of the xrefstyle attribute is simply additional information for the processing system. What effect it has, if any, is dependent on the processing system.


Common attributes and common linking attributes.


Points to the element whose content is to be used as the text of the link


Specifies a keyword or keywords identifying additional style information

See Also


<book xmlns='http://docbook.org/ns/docbook'>
<title>An Example Book</title>

<chapter xml:id="ch01"><title>XRef Samples</title>
<para>This paragraph demonstrates several features of <tag>XRef</tag>.

  <listitem><para>A straight link generates the cross-reference text:
    <xref linkend="ch02"/>.
  <listitem><para>A link to an element with an 
    <tag class="attribute">XRefLabel</tag>:
  <xref linkend="ch03"/>.
  <listitem><para>A link with an <tag class="attribute">EndTerm</tag>:
    <xref linkend="ch04" endterm="ch04short"/>.

<chapter xml:id="ch02">
  <title>The Second Chapter</title>
  <para>Some content here</para>

<chapter xml:id="ch03" xreflabel="Chapter the Third">
  <title>The Third Chapter</title>
  <para>Some content here</para>

<chapter xml:id="ch04">
  <title>The Fourth Chapter</title>
  <titleabbrev xml:id="ch04short">Chapter 4</titleabbrev>
  <para>Some content here</para>
Last revised by Norman Walsh on (git hash: c3457cab689d8fd89ba4252de204cf9a14e40acd 6a501344525f32f9834f0e4a5c3c3f8131803fa4 47fe34b28bad7941a61b9c1c17d47f6eed36cd04)