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The DocBook Schema Version 5.2

OASIS Standard

06 February 2024

This stage:

https://docs.oasis-open.org/docbook/docbook/v5.2/os/docbook-v5.2-os.docx (Authoritative)



Previous stage:

https://docs.oasis-open.org/docbook/docbook/v5.2/cs01/docbook-v5.2-cs01.docx (Authoritative)



Latest stage:

https://docs.oasis-open.org/docbook/docbook/v5.2/docbook-v5.2.docx (Authoritative)



Technical Committee:



Robert Stayton (bobs@sagehill.net), Individual


Robert Stayton (bobs@sagehill.net), Individual

Additional artifacts:

This document is one component of a Work Product that also includes:

·         RELAX NG Schemas: https://docs.oasis-open.org/docbook/docbook/v5.2/os/rng/

·         Schematron Schemas: https://docs.oasis-open.org/docbook/docbook/v5.2/os/sch/

·         XML Catalog: https://docs.oasis-open.org/docbook/docbook/v5.2/os/catalog.xml

·         NVDL Schemas: https://docs.oasis-open.org/docbook/docbook/v5.2/os/

Related work:

This document replaces or supersedes:

·         DocBook Version 5.1. Edited by Norman Walsh. 22 November 2016. OASIS Standard. http://docs.oasis-open.org/docbook/docbook/v5.1/os/docbook-v5.1-os.html. Latest version: http://docs.oasis-open.org/docbook/docbook/v5.1/docbook-v5.1.html.

·         The DocBook Schema Version 5.1.1. Edited by Robert Stayton. Latest stage: https://docs.oasis-open.org/docbook/docbook/v5.1.1/docbook-v5.1.1.html.


Update of the DocBook XML schema.


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 stage” 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 https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=docbook#technical.

TC members should send comments on this specification to the TC's email list. Others should send comments to the TC by using the "Send A Comment" button on the TC's web page at https://www.oasis-open.org/committees/docbook/.

This specification is provided under the RF on Limited Terms Mode of the OASIS IPR Policy, the mode chosen when the Technical Committee was established. For information on whether any patents have been disclosed that may be essential to implementing this specification, and any offers of patent licensing terms, please refer to the Intellectual Property Rights section of the TC's web page (https://www.oasis-open.org/committees/docbook/ipr.php).

Note that any machine-readable content (Computer Language Definitions) declared Normative for this Work Product is provided in separate plain text files. In the event of a discrepancy between any such plain text file and display content in the Work Product's prose narrative document(s), the content in the separate plain text file prevails.

Key words:

Within the normative text of this document, the terms "shall", "shall not", "should", "should not", "may", "may not", "can", and "cannot" are to be interpreted as described in "Verbal forms for expressions of provisions", Clause 7 of [ISO/IEC Directives].

Citation format:

When referencing this document, the following citation format should be used:


The DocBook Schema Version 5.2. Edited by Robert Stayton. 06 February 2024. OASIS Standard. https://docs.oasis-open.org/docbook/docbook/v5.2/os/docbook-v5.2-os.html. Latest stage: https://docs.oasis-open.org/docbook/docbook/v5.2/docbook-v5.2.html.


Copyright © OASIS Open 2024. All Rights Reserved.

Distributed under the terms of the OASIS IPR Policy, [https://www.oasis-open.org/policies-guidelines/ipr/]. For complete copyright information please see the Notices section in Appendix E.

Table of Contents

1        Introduction. 4

1.1 Changes from earlier Versions. 4

2        The DocBook RELAX NG Schema. 5

2.1 DocBook Assemblies. 5

2.2 DocBook Internationalization Tag Set 5

2.3 Xinclude. 5

2.4 Identifying DocBook Documents and Schemas. 5

3        Conformance. 6

Appendix A. References. 7

A.1 Normative References. 7

A.2 Informative References. 7

Appendix B. Security and Privacy Considerations. 8

Appendix C. Acknowledgments. 9

C.1 Special Thanks. 9

Appendix D. Revision History. 10

Appendix E. Notices. 11


1      Introduction

[All text is normative unless otherwise labeled]

DocBook is general purpose [XML] schema particularly well suited to books and papers about computer hardware and software (though it is by no means limited to these applications).

The DocBook Technical Committee maintains the DocBook schema. Starting with V5.0, DocBook is normatively available as a [RELAX NG] Schema (with some additional [Schematron] assertions).

1.1 Changes from earlier Versions

This section provides a description of significant differences from previously published, differently numbered Versions of this specification, if any. (Detailed revision history of this numbered Version should be tracked in an Appendix.)

·         Added these new synopsis elements for programming languages: enumsynopsis, macrosynopsis, packagesynopsis, typedefsynopsis, and unionsynopsis.

·         New danger admonition element.

·         New formalgroup element to support subfigures, etc.

·         New transclusion fixup attributes.

·         New class attribute on section et al to support legal sections.

·         New meta element added to info.

·         Added XInclude-enabled schema versions assemblyxi.rng and dbitsxi.rng.


2      The DocBook RELAX NG Schema

The DocBook RELAX NG Schema is distributed with this specification at the locations described under “Additional Artifacts”. DocBook is also available from the mirror on http://docbook.org/.

DocBook 5.2 includes the following schemas:

·         docbook, the main DocBook V5.2-csd01 schema.

·         docbookxi, the DocBook XInclude V5.2-csd01 schema. (This schema allows XInclude elements in many places.)

·         assembly, the DocBook Assembly V5.2-csd01 schema.

·         assemblyxi, The DocBook Assembly XInclude V5.2-csd01 schema.

·         dbits, The DocBook Internationalization Tag Set V5.2-csd01 schema.

·         dbitsxi, The DocBook Internationalization Tag Set XInclude V5.2-csd01 schema.

2.1 DocBook Assemblies

Beginning with DocBook V5.1, topic-based authoring of documents was supported.  This style of authoring creates independent units of documentation, often called topics, rather than a single narrative. In DocBook, topics can be written using the specific topic element as well as other hierarchical elements such as chapter, appendix, section, etc.

These topics can then be assembled into complete documents using the assembly schema. That schema allows the creation of an outline of references to content in other files.  When the assembly is processed, the outline is filled in with the external content to form a valid DocBook document that can then be formated or otherwise processed.

2.2  DocBook Internationalization Tag Set

The DocBook ITS schema adds elements and attributes from the Internationalization Tag Set [ITS] namespace (http://www.w3.org/2005/11/its) to provide support for internationalization and localization of DocBook documents.

The DocBook ITS schema components conform to the ITS 2.0 Recommendation produced by the World Wide Web Consortium (W3C).

2.3 Xinclude

Each of the DocBook schemas is available in a version that directly supports the [Xinclude] W3C Recommendation.  This schema version allows the direct replacement of many DocBook elements with the xinclude element and still validate.

To ensure that a document is fully DocBook conformant, however, the document should be processed to resolve all the xinclude elements and then validated against the non-xinclude DocBook schema.

2.4 Identifying DocBook Documents and Schemas

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.

For systems that can make use of public identifiers, e.g., systems where the informative DTD is being used, the following public identifier should be used for DocBook V5.2: “-//OASIS//DTD DocBook V5.2//EN//XML”.

3      Conformance

This specification normatively defines DocBook V5.2 with a RELAX NG grammar and a set of Schematron assertions. A conformant DocBook V5.2 document must be valid according to both the grammar and the assertions.

The reference documentation describes additional constraints and processing expectations. A conformant DocBook V5.2 document should respect those constraints and anticipate those processing expectations.

See 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.

Appendix A. References

This appendix contains the normative and informative references that are used in this document. Normative references are specific (identified by date of publication and/or edition number or Version number) and Informative references are either specific or non-specific.

While any hyperlinks included in this appendix were valid at the time of publication, OASIS cannot guarantee their long term validity.

A.1 Normative References

The following documents are referenced in such a way that some or all of their content constitutes requirements of this document.


[ISO/IEC Directives] ISO/IEC Directives, Part 2 (Eighth edition) Principles and rules for the structure and drafting of ISO and IEC documents, International Organization for Standardization and International Electrotechnical Commission, 2018. https://www.iso.org/sites/directives/current/part2/index.xhtml.

[ITS] David Filip, Shaun McCance, et. al., editors. Internationalization Tag Set (ITWS) Version 2.0. World Wide Web Consortium, 29 October 2013.

[Xinclude] Jonathan Marsh, David Orchard, Daniel Veillard, editors. XML Inclusions (XInclude) Version 1.0 (Second Edition). World Wide Web Consortium, 15 November 2006.

[XML] Tim Bray, Jean Paoli, C. M. Sperberg-McQueen, et. al., editors. Extensible Markup Language (XML) 1.0 (Fourth Edition). World Wide Web Consortium, 16 August 2006.

[XLink11] Steven DeRose, Eve Maler, David Orchard, Norman Walsh, editors. XML Linking Language (XLink) Version 1.1. World Wide Web Consortium, 2005.

[W3C XML Datatypes] Paul V. Biron and Ashok Malhotra, editors. XML Schema Part 2: Datatypes. World Wide Web Consortium, 2000.

[RELAX NG] ISO/IEC 19757-2:2008 Information Technology—Document Schema Definition Language (DSDL)—Part 2: Regular-grammar-based validation—RELAX NG.

[Schematron] ISO/IEC 19757-3:2006 Information Technology—Document Schema Definition Language (DSDL)—Part 3: Rule-based validation—Schematron.

[RFC 3023] IETF (Internet Engineering Task Force). RFC 3023: XML Media Types. M. Murata, S. St. Laurent, D. Kohn. 2001.

[DocBook 5: TDG] Norman Walsh. DocBook 5.0: The Definitive Guide. O'Reilly Media. April 2010.

[DocBook 5.1: TDG] Norman Walsh. DocBook 5.1: The Definitive Guide.

[DocBook 5.2: TDG] Norman Walsh. DocBook 5.2: The Definitive Guide.

A.2 Informative References

The following referenced documents are not required for the application of this document but may assist the reader with regard to a particular subject area.


[DocBookXSL] Robert Stayton, DocBook XSL: The Complete Guide (Fourth Edition). Sagehill Enterprises, Santa Cruz CA, 2007.

[DocBookIssues] DocBook Issues Tracker is available on GitHub at https://github.com/docbook/docbook/issues

Appendix B. Security and Privacy Considerations

Several DocBook elements may refer to arbitrary URIs. In this case, consider the security issues of RFC 2396, section 7.

Appendix C. Acknowledgments

C.1 Special Thanks

Substantial contributions to this document from the following individuals are gratefully acknowledged:


[Dick Hamilton, | Individual Member]

[Scott Hudson, ServiceNow, Inc. | Secretary]

[Jirka Kosek, | Individual Member]

[Larry Rowland, Hewlett Packard | Individual Member]

[Robert Stayton, Sagehill Enterprises | Chair]

[Norman Walsh | Individual Member]


Appendix D. Revision History

Revisions made since the initial stage of this numbered Version of this document will be tracked here.





Changes Made

[Rev number]

[Rev Date]

[Modified By]

[Summary of Changes]


Appendix E. Notices

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