XML format

DocBook 5

A semantic vocabulary for technical books, articles, references, procedures, code listings, and cross-references.

DocBook describes what technical content means rather than how it looks. Books, chapters, sections, procedures, commands, parameters, and program listings can be transformed into HTML, PDF, EPUB, or help-system output.

DocBook 5 moved the vocabulary into a namespace and is commonly validated with RELAX NG. Older DocBook 4 documents are usually namespace-free, so the root namespace is the fastest version clue.

Constraints that bite

DocBook 5 elements belong to http://docbook.org/ns/docbook.
The vocabulary is semantic; presentation is supplied by a transformation or publishing toolchain.
Cross-reference targets use xml:id and must remain unique within the document.
DocBook 4 and 5 documents require different validation rules and migration handling.

Root element: <book>
Media type: application/docbook+xml
Extensions: .xml, .dbk
Namespaces: http://docbook.org/ns/docbook
XMLDir label: xml

Specification: DocBook 5.2 reference

A minimal valid document

Every example on this site is checked against the same parser the workspace uses, so what you see below is known to be well-formed.

docbook.xml

<?xml version="1.0" encoding="UTF-8"?>
<book xmlns="http://docbook.org/ns/docbook" version="5.2">
  <info><title>Deploying the catalog</title></info>
  <chapter xml:id="install">
    <title>Install</title>
    <para>Run <command>catalogctl setup</command>.</para>
  </chapter>
</book>

Validate your own DocBook 5 Extract its XPath map