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<!ENTITY pversion "csprd01">
<!ENTITY version "os">
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<articleinfo>

<title>DocBook Version 5.1</title>

<releaseinfo role="cvs">
<?nospell-start?>$Id$
</releaseinfo>
  <releaseinfo role="track">Standards Track Work Product</releaseinfo>

<productname>&name;-&version;</productname>
<productnumber>&version;</productnumber>

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<releaseinfo role="committee"><ulink url="http://www.oasis-open.org/committees/docbook/">OASIS DocBook Technical Committee</ulink></releaseinfo>

  <authorgroup>
    <editor>     
        <firstname>Norman</firstname>
        <surname>Walsh</surname> 
        <contrib><ulink url="mailto:norman.walsh@marklogic.com">norman.walsh@marklogic.com</ulink></contrib>
       <affiliation>       
          <orgname>Individual</orgname>
       </affiliation>
      
    </editor>
    <othercredit class="other" role="Chair">     
      <firstname>Robert</firstname>
      <surname>Stayton</surname>
      <contrib><ulink url="mailto:bobs@sagehill.net">bobs@sagehill.net</ulink></contrib>
      <affiliation>       
        <orgname>Individual</orgname>
      </affiliation>
      
    </othercredit>
    
  </authorgroup>
  


<pubdate>&pubdate;</pubdate>

<copyright><year>2016</year>
<holder>OASIS Open, Inc. All Rights Reserved.</holder></copyright>
  
  <legalnotice role="additional">
    <title>Additional Artifacts</title>
    <para>This prose specification is one component of a Work Product that also includes:</para>
    <itemizedlist spacing="compact">
      <listitem>
        <para>Schemas: <ulink url="http://docs.oasis-open.org/docbook/docbook/v5.1/os/schemas/">http://docs.oasis-open.org/docbook/docbook/v5.1/os/schemas/</ulink></para>
      </listitem>
      <listitem>
        <para>DocBook V4.x conversion tools: <ulink url="http://docs.oasis-open.org/docbook/docbook/v5.1/os/tools/">http://docs.oasis-open.org/docbook/docbook/v5.1/os/tools/</ulink></para>
      </listitem>
    </itemizedlist>
  </legalnotice>

  <legalnotice role="related"><title>Related Work</title>
    <para>This specification replaces or supersedes:</para>
    <itemizedlist spacing="compact">
      <listitem><para>The DocBook Schema Version 5.0. 1 November 2009. OASIS Standard.  
        <ulink url="http://docs.oasis-open.org/docbook/specs/docbook-5.0-spec.html">http://docs.oasis-open.org/docbook/specs/docbook-5.0-spec.html</ulink></para>
      </listitem>
    </itemizedlist>
    
  </legalnotice>
  
<legalnotice role="namespaces"><title>Declared XML Namespaces</title>
  <para>
    <ulink url="http://docbook.org/ns/docbook">http://docbook.org/ns/docbook</ulink></para>

</legalnotice>

  <abstract>
    <para>DocBook is a general purpose <xref linkend="xml-rec"/> schema
      particularly well suited to books and papers about computer hardware
      and software (though it is by no means limited to these applications).
    </para>
    <para>The Version 5.1 release introduces assemblies for topic-oriented
      authoring. It also addresses a selection of bugs and feature requests.
    </para>
    <para>The Technical Committee provides the DocBook 5.1 schema in other
      schema languages, including W3C XML Schema and an
      XML DTD, but the RELAX NG Schema is the normative schema.</para>
  </abstract>

<legalnotice role="status"><title>Status</title>

  <para>This document was last revised or approved by the membership of OASIS on the above date. The level of approval is also
    listed above. Check the "Latest version" location noted above for
    possible later revisions of this document. Any other numbered Versions
    and other technical work produced by the Technical Committee (TC) are
    listed at
    <ulink url="https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=docbook#technical">https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=docbook#technical</ulink>.</para>
  
  <para>Technical Committee members should send comments on this
    specification to the Technical Committee's email list. Others should
    send comments to the Technical Committee by using the
    "<ulink url="https://www.oasis-open.org/committees/comments/index.php?wg_abbrev=docbook">Send A Comment</ulink>"
    button on the Technical Committee's web page at
    <ulink url="https://www.oasis-open.org/committees/docbook/">https://www.oasis-open.org/committees/docbook/</ulink>.</para>
  
  <para>For information on whether any patents have been disclosed that may
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  <para>Any other numbered Versions and other technical work produced by
    the Technical Committee (TC) are listed at
    <ulink url="https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=docbook#technical">https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=docbook#technical</ulink>.</para>
  
</legalnotice>

  <legalnotice role="citationformat"><title>Citation format</title>
    <para>When referencing this specification, the following citation format should be used:</para>
    <para><emphasis role="bold">[DocBook-5.1]</emphasis><?lb?><emphasis>DocBook Version 5.1</emphasis>. Edited by Norman Walsh. 22 November 2016. OASIS Standard.
      <ulink url="http://docs.oasis-open.org/docbook/docbook/v5.1/os/docbook-v5.1-os.html">http://docs.oasis-open.org/docbook/docbook/v5.1/os/docbook-v5.1-os.html</ulink>
      Latest version: <ulink url="http://docs.oasis-open.org/docbook/docbook/v5.1/docbook-v5.1.html">http://docs.oasis-open.org/docbook/docbook/v5.1/docbook-v5.1.html</ulink>.</para>
  </legalnotice>

  <legalnotice role="notices"><title>Notices</title>
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      may be found at the OASIS website.</para>
    
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  </legalnotice>
</articleinfo>

<section id="s.intro">
<title>Introduction</title>

<section id="s.background">
<title>Background</title>

<para>DocBook is general purpose
<xref linkend="xml-rec"/>
schema particularly well suited to books and papers about computer
hardware and software (though it is by no means limited to these
applications).
</para>

<para>The <ulink url="https://www.oasis-open.org/committees/docbook/">DocBook
Technical Committee</ulink> maintains the DocBook schema. Starting
with V5.0, DocBook is normatively available as a
<biblioref linkend="iso19757-2"/> Schema (with some additional
<biblioref linkend="iso19757-3"/> assertions).
A non-normative <biblioref linkend="xmlschema-1"/> version will
be published when it is available.
DocBook builds on existing XML technologies: it uses
<biblioref linkend="xlink11"/> for linking,
<biblioref linkend="xmlschema-2"/> for atomic data types, and
anticipates the use of
<biblioref linkend="xinclude"/> for transclusion.</para>

<note>
<para>DocBook has been
under active maintenance for more than 20 years, it began life as
an <biblioref linkend="iso8879"/> document type definition.</para>
</note>

<para>The Version 5.1 introduces assemblies for topic-oriented authoring
and addresses a selection of bugs and feature requests.</para>

<para>The DocBook Technical Committee welcomes bug reports and
requests for enhancement (RFEs) from the user community.
Please send comments and requests for enhancement to the
DocBook comments list,
<ulink url="mailto:docbook-comment@lists.oasis-open.org">docbook-comment@lists.oasis-open.org</ulink> mailing list.
Outstanding requests can be seen in the archives as well as
in the
issues tracker on 
<ulink url="https://github.com/docbook/docbook">Github</ulink>
<ulink url="https://github.com/docbook/docbook/issues">Issues</ulink>
interface.
</para>
</section>

<section id="s.terminology"><title>Terminology</title>
<para>The key words <glossterm>must</glossterm>, <glossterm>must
not</glossterm>, <glossterm>required</glossterm>,
<glossterm>shall</glossterm>, <glossterm>shall not</glossterm>,
<glossterm>should</glossterm>, <glossterm>should not</glossterm>,
<glossterm>recommended</glossterm>, <glossterm>may</glossterm>, and
<glossterm>optional</glossterm> in this OASIS Standard are to be
interpreted as described in <xref linkend="rfc2119"/>.</para>
</section>

<section id="normative.refs">
<title>Normative References</title>

<bibliolist>
<bibliomixed id="xml-rec"><abbrev>XML</abbrev>T.&#xa0;Bray,
J.&#xa0;Paoli,&#xa0;M., E.&#xa0;Maler, F.&#xa0;Yergeau, Editors,
<citetitle><ulink url="http://www.w3.org/TR/REC-xml/">Extensible Markup
(XML) 1.0 (Fifth Edition)</ulink></citetitle>, W3C Recommendation,
26 November 2008.
</bibliomixed>
<bibliomixed id="xlink11"><abbrev>XLink</abbrev>Steven DeRose, Eve Maler,
David Orchard, Norman Walsh, editors.
<citetitle><ulink url="http://www.w3.org/TR/xlink11/">XML Linking Language (XLink)
Version 1.1</ulink></citetitle>.
World Wide Web Consortium, 2005.
</bibliomixed>
<bibliomixed id="xinclude"><abbrev>XInclude</abbrev>Jonathan Marsh, David
Orchard, Daniel Veillard, Norman Walsh, editors.
<citetitle><ulink url="http://www.w3.org/TR/xinclude/">XML
Inclusions (XInclude) Version 1.0 (Second Edition)</ulink></citetitle>.
World Wide Web Consortium, 2006.
</bibliomixed>
<bibliomixed id="xmlschema-2"><abbrev>W3C XML Datatypes</abbrev>Paul V. Biron
and Ashok Malhotra, editors.
<citetitle><ulink url="http://www.w3.org/TR/xmlschema-2/">XML Schema Part 2: Datatypes Second Edition</ulink></citetitle>.
World Wide Web Consortium, 2004.
</bibliomixed>
<bibliomixed id="its20"><abbrev>ITS</abbrev>David Filip, Shaun McCance,
Dave Lewis, et. al., editors.
<citetitle><ulink url="http://www.w3.org/TR/its20/">International Tag Set
(ITS) 2.0</ulink></citetitle>.
World Wide Web Consortium, 2013.
</bibliomixed>
<bibliomixed id="iso19757-2"><abbrev>RELAX NG</abbrev>
<citetitle><ulink url="http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=52348">ISO/IEC 19757-2:2008 Information Technology—Document
Schema Definition Language (DSDL)—Part 2: Regular-grammar-based
validation—RELAX NG</ulink></citetitle>.
  Publicly available at:&#160;<citetitle><ulink url="http://standards.iso.org/ittf/PubliclyAvailableStandards/c052348_ISO_IEC_19757-2_2008(E).zip"/></citetitle>.
</bibliomixed>
<bibliomixed id="iso19757-3"><abbrev>Schematron</abbrev>
<citetitle><ulink url="http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=40833">ISO/IEC 19757-3:2006 Information Technology—Document
Schema Definition Language (DSDL)—Part 3: Rule-based
validation—Schematron</ulink>
Publicly available at:&#160;<ulink url="http://standards.iso.org/ittf/PubliclyAvailableStandards/c040833_ISO_IEC_19757-3_2006(E).zip"/>.
</citetitle>.
</bibliomixed>
<bibliomixed id="rfc2119"><abbrev>RFC 2119</abbrev>Bradner, S.
“Key words for use in RFCs to Indicate Requirement Levels”, BCP 14,
RFC 2119, March 1997,
<citetitle><ulink url="http://www.rfc-editor.org/info/rfc2119"/></citetitle>.
</bibliomixed>
<bibliomixed id="rfc7303"><abbrev>RFC 7303</abbrev>Thompson, H.
and C. Lilley, "XML Media Types", RFC 7303, July 2014,
<citetitle><ulink url="http://www.rfc-editor.org/info/rfc7303"/></citetitle>.
</bibliomixed>
<bibliomixed id="bib.docbooktdg51"><abbrev>DocBook 5.1: TDG</abbrev>
Norman Walsh.
<citetitle><ulink url="http://docbook.org/tdg51/en/html/">DocBook 5.1:
The Definitive Guide</ulink>.</citetitle>
</bibliomixed>
</bibliolist>
</section>

<section id="non-normative.refs">
<title>Non-Normative References</title>
<bibliolist>
<bibliomixed id="bib.docbooktdg5"><abbrev>DocBook 5: TDG</abbrev>
Norman Walsh.
<citetitle><ulink url="http://shop.oreilly.com/product/9780596805012.do">DocBook 5.0:
The Definitive Guide</ulink>. O'Reilly Media. April 2010.</citetitle>
</bibliomixed>
<bibliomixed id="iso8879"><abbrev>SGML</abbrev>JTC 1, SC 34.
<citetitle>ISO 8879:1986
Information processing -- Text and office systems --
Standard Generalized Markup Language (SGML)</citetitle>. 1986.
</bibliomixed>
<bibliomixed id="xmlschema-1"><abbrev>W3C XML Schema</abbrev>Henry S. Thompson,
David Beech, Murray Maloney, et. al., editors.
<citetitle><ulink url="http://www.w3.org/TR/xmlschema-1/">XML Schema Part 1: Structures Second Edition</ulink></citetitle>.
World Wide Web Consortium, 2004.
</bibliomixed>
</bibliolist>
</section>
</section>

<section id="s.docbook">
<title>The DocBook RELAX NG Schema</title>

<section id="s.distribution">
<title>Distribution</title>

<para>The DocBook RELAX NG Schema (and associated non-normative schemas
and tools) are distributed with this specification.
DocBook is also available from the mirror on
<ulink url="http://docbook.org/"/>.
</para>

<para>This prose specification is one component of a Work Product
that also includes:</para>
  <itemizedlist>
    <listitem>
      <para>RELAX NG DocBook Schema accessible from <ulink url="&this-loc;/schemas/rng/docbook.rnc">&this-loc;/schemas/rng/docbook.rnc</ulink></para>
    </listitem>
    <listitem>
      <para>RELAX NG DocBook Assembly Schema accessible from <ulink url="&this-loc;/schemas/rng/assembly.rnc">&this-loc;/schemas/rng/assembly.rnc</ulink></para>
    </listitem>
    <listitem>
      <para>RELAX NG DocBook+ITS Schema accessible from <ulink url="&this-loc;/schemas/rng/dbits.rnc">&this-loc;/schemas/rng/dbits.rnc</ulink></para>
    </listitem>
    <listitem>
      <para>RELAX NG DocBook+XInclude Schema accessible from <ulink url="&this-loc;/schemas/rng/docbookxi.rnc">&this-loc;/schemas/rng/docbookxi.rnc</ulink></para>
    </listitem>
    <listitem>
      <para>RELAX NG DocBook Schematron accessible from <ulink url="&this-loc;/schemas/sch/docbook.sch">&this-loc;/schemas/sch/docbook.sch</ulink></para>
    </listitem>
    <listitem>
      <para>RELAX NG DocBook Assembly Schematron Schema accessible from <ulink url="&this-loc;/schemas/sch/assembly.sch">&this-loc;/schemas/sch/assembly.sch</ulink></para>
    </listitem>
    <listitem>
      <para>RELAX NG DocBook+ITS Schematron accessible from <ulink url="&this-loc;/schemas/sch/docbookxi.sch">&this-loc;/schemas/sch/docbookxi.sch</ulink></para>
    </listitem>
    <listitem>
      <para>RELAX NG DocBook+XInclude Schematron accessible from <ulink url="&this-loc;/schemas/sch/docbookxi.sch">&this-loc;/schemas/sch/docbookxi.sch</ulink></para>
    </listitem>
    <listitem>
      <para>An XML Catalog accessible from <ulink url="&this-loc;/schemas/catalog.xml">&this-loc;/schemas/catalog.xml</ulink></para>
    </listitem>
    <listitem>
      <para>An NVDL Schema accessible from <ulink url="&this-loc;/schemas/docbook.nvdl">&this-loc;/schemas/docbook.nvdl</ulink></para>
    </listitem>
    <listitem>
      <para>DocBook V4.x conversion tools accessible from <ulink url="&this-loc;/tools/">&this-loc;/tools/</ulink></para>
    </listitem>
    
  </itemizedlist>
  
</section>
</section>

<section id="s.identifying">
<title>Identifying DocBook Documents and Schemas</title>

<para>For systems that can make use of public identifiers, e.g., systems
where the informative DTD is being used, the following
public identifier <glossterm>should</glossterm> be used for DocBook V5.1:
“<literal>-//OASIS//DTD DocBook V5.1//EN//XML</literal>”.</para>

<note>
<para>Historically, when DocBook was defined by a DTD, DocBook
documents could be identified by the presence of standard public
and/or system identifiers in the document type declaration. RELAX NG,
the normative schema language for DocBook V5.0, does not provide
any equivalent mechanism.</para>
</note>

</section>

<section id="s.conformance">
<title>Conformance</title>

<para>This specification normatively defines DocBook V5.1 with a RELAX NG
grammar and a set of Schematron assertions. A conformant DocBook V5.1 document
<glossterm>must</glossterm> be valid according to both the grammar and the
assertions.</para>

<para>DocBook documents are described by a set of schemas:</para>

<itemizedlist>
<listitem>
<para>“Plain” DocBook documents and DocBook Assembly documents. The schema
for assembly documents is separate as a convenience for authors, it is
conceptually part of the whole set of DocBook documents.
</para>
</listitem>
<listitem>
<para>DocBook + International Tag Set (ITS) Version 2.0; this schema allows
authors to write valid DocBook documents that satisfy
ITS Conformance Type 1 as defined in <biblioref linkend="its20"/>.
</para>
</listitem>
<listitem>
<para>DocBook + XInclude markup; this schema is not normative. It allows
authors to write documents which mix DocBook markup and XInclude in many
(but perhaps not all) reasonable places.
</para>
</listitem>
</itemizedlist>

  <para>The schemas in question are those listed in <xref linkend="s.distribution"/>.</para>


<para>The reference documentation (see <biblioref
linkend="bib.docbooktdg51"/>) describes general processing
expectations for each element and some of the circumstances in which
they may or may not apply. Understanding and conforming to these
processing expectations where practical is likely to improve
interoperability.</para>

<note>
<para><biblioref linkend="bib.docbooktdg5"/>, the reference
documentation for DocBook V5.0, much of which still applies to DocBook
V5.1, is also available in published form from
<citetitle>O'Reilly Media</citetitle>.
</para>
</note>
</section>

<section id="s.relnotes">
<title>Release Notes</title>

<para>See <ulink url="http://www.relaxng.org/"/> for a list of tools that
can validate an XML document using RELAX NG. Note that not all products
are capable of evaluating the Schematron assertions in the schema.</para>

</section>

<!--
<appendix id="a.mimetype">
<title>The DocBook Media Type</title>

<para>This appendix registers a new MIME media type,
<quote><code>application/docbook+xml</code></quote>.</para>

<section id="media-type-registration">
<title>Registration of MIME media type application/docbook+xml</title>

<variablelist>
<varlistentry>
<term>MIME media type name:</term>
<listitem>
<para><code>application</code>
</para>
</listitem>
</varlistentry>

<varlistentry>
<term>MIME subtype name:</term>
<listitem>
<para><code>docbook+xml</code>
</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Required parameters:</term>
<listitem>
<para>None.
</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Optional parameters:</term>
<listitem>
  <variablelist>
  <varlistentry>
  <term><code>charset</code></term>
  <listitem>

  <para>This parameter has identical semantics to the <code>charset</code>
parameter of the <code>application/xml</code> media type as
specified in <xref linkend="rfc7303"/> or its successors.
</para>
  </listitem>
  </varlistentry>
  </variablelist>
</listitem>
</varlistentry>

<varlistentry>
<term>Encoding considerations:</term>
<listitem>
<para>By virtue of DocBook XML content being XML, it has the same
considerations when sent as <quote><code>application/docbook+xml</code></quote>
as does XML. See <xref linkend="rfc7303"/>, Section 3.2.
</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Security considerations:</term>
<listitem>
<para>Several DocBook elements may refer to arbitrary URIs.
In this case, consider the security issues of RFC 2396, section 7.
</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Interoperability considerations:</term>
<listitem>
<para>None.</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Published specification:</term>
<listitem>
<para>This media type registration is for DocBook documents as described by
<xref linkend="bib.docbooktdg5"/>.</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Applications which use this media type:</term>
<listitem>
<para>There is no experimental, vendor specific, or personal tree
predecessor to <quote><code>application/docbook+xml</code></quote>,
reflecting the fact that no applications currently recognize it. This
new type is being registered in order to allow for the
deployment of DocBook on the World Wide Web as a first class XML
application.
</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Additional information:</term>
<listitem>
  <variablelist>
  <varlistentry>
  <term>Magic number(s):</term>

  <listitem>
  <para>There is no single initial octet sequence that is always present in
DocBook documents.
  </para>
  </listitem>
  </varlistentry>

  <varlistentry>
  <term>File extension(s):</term>
  <listitem>
  <para>DocBook documents are most often identified with the extension
<quote><filename class="extension">.xml</filename></quote>.
  </para>
  </listitem>
  </varlistentry>

  <varlistentry>
  <term>Macintosh File Type Code(s):</term>
  <listitem>
  <para>TEXT</para>
  </listitem>
  </varlistentry>
  </variablelist>
</listitem>
</varlistentry>

<varlistentry>
<term>Person &amp; email address to contact for further information:</term>
<listitem>
<para>Norman Walsh, <email>ndw@nwalsh.com</email>.</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Intended usage:</term>
<listitem>
<para>COMMON</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Author/Change controller:</term>
<listitem>
<para>The DocBook specification is a work product of the DocBook
Technical Committee at OASIS.</para>
</listitem>
</varlistentry>
</variablelist>
</section>

<section id="fragid">
<title>Fragment Identifiers</title>

<para>For documents labeled as
<quote><code>application/docbook+xml</code></quote>,
the fragment
identifier notation is exactly that for
<quote><code>application/xml</code></quote>,
as specified in <xref linkend="rfc7303"/> or its successors.</para>
</section>
</appendix>
-->

<appendix id="a.committee" role="non-normative">
<title>Acknowledgements</title>

<para>The following individuals have participated in the creation of
this specification and are gratefully acknowledged:
<simplelist type="inline">
<member>Steve Cogorno</member>
<member>Gary Cornelius</member>
<member>Adam Di Carlo</member>
<member>Paul Grosso</member>
<member>Dick Hamilton (Secretary)</member>
<member>Nancy Harrison</member>
<member>Scott Hudson</member>
<member>Mark Johnson</member>
<member>Gershon Joseph</member>
<member>Jirka Kosek</member>
<member>Larry Rowland</member>
<member>Michael Smith</member>
<member>Robert Stayton (Chair)</member>
<member>Norman Walsh (Editor)</member>
</simplelist>.</para>
</appendix>

  <appendix id="changes"  role="non-normative">
<title>Revision History</title>

<section id="s.51">
<title>Changes in DocBook V5.1</title>

<para>DocBook V5.1 fixes a number of bugs, summarized below, and adds
a significant new feature designed for the purpose of topic-based
authoring: assemblies.</para>

<section id="s.assembly">
<title>Assemblies</title>

<para>One modern school of thought on technical documentation stresses
the development of independent units of documentation, often called
topics, rather than a single narrative. Instead of writing something
that DocBook users would easily recognize as a book consisting of a
preface, several consecutive chapters, and a few appendixes, the
author (or authors) write a set of discrete topics covering different aspects of
the system as if they were wholly independent.</para>

<para>In a typical online presentation system, for example the world
wide web or online help, each topic is a page that stands alone.
Except, of course, that just as no man is an island, no topic is
completely unrelated to the other topics that are available.</para>

<para>From any given topic, there may be topics of obviously related
interest. The nature of the relationships may vary. Some topics are
related by physical proximity (if you're interested in the ink
cartridges in a printer, you may also be interested in the print
head), others by their procedural nature (adding or replacing memory,
adding or replacing a hard drive, or even changing the CPU are all
topics that might logically follow a topic that describes how to open
the computer case).</para>

<para>In a single narrative, it is the responsibility of the author to
manage these relationships. He or she can reasonably assume that
anyone reading chapter 4 has read chapters 1, 2, and 3. If the reader
needs to be directed elsewhere, a cross reference can be used (for
example, “for more information on paper jams, see Section 3.5,
<citetitle>The Paper Path</citetitle>”).</para>

<para>In a topic-oriented system, authors are explicitly instructed to
write independent units. No linear order can be assumed and many forms
of explicit cross-reference are discouraged.</para>

<para>Documentation managers treat the library of available topics
very much as programmers treat libraries of available functions. Just
as any given program can pick and choose from the available libraries,
the documentation for any given system can pick and choose from the
available topics.</para>

<para>If you imagine a large documentation group managing the documentation
for several related systems (different models of printer, different
configurations of a software system, computers assembled from
different components, etc.) it's easy to see the appeal of topic-oriented
authoring.</para>

<para>In a successful deployment, you might find a library of say 1,000
topics which, taken together, document five or six related systems, each of
which uses 700-800 topics. Some topics are used in every system, many are
used in several systems, and a small number of topics are unique to a
specific system.</para>

<para>In order to make such a documentation platform functional, you
need not only the individual topics, but also some sort of “map” or
“assembly” file that describes which topics from the library are used,
what relationships exist between them and, at least for print
presentation, what linear order is to be imposed upon them.</para>

<para>DocBook uses assemblies for this purpose, see
<citetitle><ulink url="http://docbook.org/tdg51/en/html/">DocBook 5.1:
The Definitive Guide</ulink></citetitle>,
<ulink url="http://docbook.org/tdg51/en/html/ch06.html">Chapter 6</ulink>.
</para>
</section>
</section>

<section id="s.51CR3">
<title>Changes in DocBook V5.1CR3</title>

<para>This release contains a bug fix.</para>

<orderedlist>
<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/305/">#305</ulink>;
made navigational components optional in <sgmltag>sect1</sgmltag>.</para>
</listitem>
</orderedlist>
</section>

<section id="s.51CR2">
<title>Changes in DocBook V5.1CR2</title>

<para>This release contains bug fixes and improvements over V5.1CR1.</para>

<orderedlist>
<listitem>
<para>Use
final ITS 2.0 schemas.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/303/">#303</ulink>;
moved multimediaparam into the *data elements and allow the
*data elements to be repeated.
</para>
</listitem>

<listitem>
<para>Added
RDFa Lite attributes to DocBook; removed the separate customization layer.
</para>
</listitem>

<listitem>
<para>Added
source for catalog.xml.
</para>
</listitem>
</orderedlist>
</section>

<section id="s.51CR1">
<title>Changes in DocBook V5.1CR1</title>

<para>This release contains bug fixes and improvements over V5.0.</para>

<orderedlist>
<listitem>
<para>Updated
the <filename>db4-upgrade.</filename> script.
</para>
</listitem>

<listitem>
<para>Added
an RDFa Lite extension schema.
</para>
</listitem>

<listitem>
<para>Merged
ITS changes.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/300/">#300</ulink>;
added a class to see/seealso to handle the 'under' case.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/277/">#277</ulink>;
added a result element.
</para>
</listitem>

<listitem>
<para>Added
@its:version, improved better handling of extensibility.
</para>
</listitem>

<listitem>
<para>Merged
pull request <ulink url="https://github.com/docbook/docbook/issues/5">#5</ulink> from kosek/master.
</para>
</listitem>

<listitem>
<para>Updated
ITS to support ITS 2.0
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/298/">#298</ulink>;
don't allow secondary without primary in indexterm.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/295/">#295</ulink>;
allow navigation components at the beginnings of sections.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/293/">#293</ulink>;
removed spurious, duplicate 'other' value.
</para>
</listitem>

<listitem>
<para>Attempt
to implement the whole proposal for accessability attributes in CALS tables.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/293/">#293</ulink>;
allow admonitions in formal objects.
</para>
</listitem>

<listitem>
<para>Fixed:
issue <ulink url="http://sourceforge.net/p/docbook/rfes/299/">#299</ulink>;
allow articles in sets.
</para>
</listitem>

<listitem>
<para>Added
scope attribute to CALS tables.
</para>
</listitem>

<listitem>
<para>Removed
format attribute from output element; the standard effectivity attribute
outputformat can be used instead.
</para>
</listitem>

<listitem>
<para>Added
outputformat as an effectivity attribute.
</para>
</listitem>

<listitem>
<para>Added:
AltGr and Return to keycap class values.
</para>
</listitem>

<listitem>
<para>Renamed
fileref attribute to href in on resources in assemblies.
</para>
</listitem>

<listitem>
<para>Fixed
bug in Schematron assertions about XLink, thanks to Hussein Shafie
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/292/">#292</ulink>;
added pgwide to informalexample and informalequation.
</para>
</listitem>

<listitem>
<para>Made
info on structure and module optional in assemblies.
</para>
</listitem>

<listitem>
<para>Implemented
recent TC decisions about assemblies.
</para>
</listitem>

<listitem>
<para>Adopted
the recent proposals to add attributes/parameters to audio and video objects.
</para>
</listitem>

<listitem>
<para>Fixed
reference to broken pattern; make sure linking attributes are on areas.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/285/">#285</ulink>;
made content optional in components and sections.
</para>
</listitem>

<listitem>
<para>Allow
link in extendedlink, in preparation for arc and locator being removed in V6.0.
</para>
</listitem>

<listitem>
<para>Added
extendedlink changes to the V6.0 future use comments.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/289/">#289</ulink>;
allow multiple procedure elements in task.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/288/">#288</ulink>;
allow tag elements to nest
</para>
</listitem>

<listitem>
<para>Reworked
XLink attributes to support simple/extended links.
</para>
</listitem>

<listitem>
<para>Added
pattern for imagedata, SVG, and MathML content
(so that it can be extended by the XInclude schema).
</para>
</listitem>

<listitem>
<para>Added
XInclude to images and equations; allow foreign,
namespace-qualified attributes on the xi:include element.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/276/">#276</ulink>;
broaden content model of contrib.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/282/">#282</ulink>;
update HTML informaltable attributes.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/283/">#283</ulink>;
allow production to contain rhs+.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/284/">#284</ulink>;
support ISTC as a biblioid class.
</para>
</listitem>

<listitem>
<para>Attempt
to implement Larry's latest suggestions about assemblies.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/281/">#281</ulink>;
allow xi:include in set.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/280/">#280</ulink>;
added securitycontext and other to systemitem.
</para>
</listitem>

<listitem>
<para>Fixed
issue <ulink url="http://sourceforge.net/p/docbook/rfes/279/">#279</ulink>;
allow dedication in article.
</para>
</listitem>

<listitem>
<para>Changed
Schematron namespace to official ISO Schematron URI.
</para>
</listitem>

<listitem>
<para>Allow
topic in chapter and appendix (as an alternative to narrative content)
per May 2010 TC meeting.
</para>
</listitem>

<listitem>
<para>Fixed
content model of book and part to make topic an alternative,
not part of the component mixture.
</para>
</listitem>

<listitem>
<para>Allow
the other major components of an assembly to be top level elements (so
they can be stored in separate files, for example).
</para>
</listitem>

<listitem>
<para>Allow
an assembly without any structure elements.
</para>
</listitem>

<listitem>
<para>Tweak
assembly schemas.
</para>
</listitem>

<listitem>
<para>Allow
override element in assemblies.
</para>
</listitem>

<listitem>
<para>Generalized
toc/index to db.navigation.components in assembly structure and module
for consistency
</para>
</listitem>

<listitem>
<para>Updated:
in assembly, if at least one resource is required, then at least one
structure should be required as well.
</para>
</listitem>

<listitem>
<para>Removed
description attribute from assemblies (no content in attributes!);
added some refpurpose documentation for attributes and attribute values.
</para>
</listitem>

<listitem>
<para>Added
refpurpose for type attribute.
</para>
<!--relaxng/docbook/src/topic.rnc-->
</listitem>
</orderedlist>

</section>
</appendix>



</article>
<?nospell-end?>

