The DocBook Document Type

Committee Specification, 02 June 2006

Document identifier:

docbook-4.5-spec-cs-03 (.xml, .html, .pdf)



Norman Walsh, Sun Microsystems, Inc. 


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

The Version 4.5 release is a maintenance release. It introduces no backwards-incompatible changes.


This Committee Specification was approved for publication by the OASIS DocBook Technical Committee. It represents the consensus of the committee.

Please send comments on this specification to the list. To subscribe, please use the OASIS Subscription Manager.

The errata page for this specification is at

Table of Contents

1. Introduction
2. Terminology
3. The DocBook Document Type V4.5
3.1. Changes in DocBook V4.5CR3
3.2. Changes in DocBook V4.5CR2
3.3. Changes in the Public Review Draft of DocBook V4.5
3.4. Changes in DocBook V4.5CR1
3.5. Changes in DocBook V4.5b1
4. Release Notes


A. The DocBook Media Type
1. Registration of MIME media type application/docbook+xml
2. Fragment Identifiers
B. OASIS DocBook Technical Committee (Non-Normative)
C. Notices
D. Intellectual Property Rights
E. Revision History

1. Introduction

DocBook is general purpose XML and SGML document type 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. DocBook is officially available as a Document Type Definition (DTD) for both XML and SGML. It is unofficially available in other forms as well.

The Version 4.5 release is a maintainance release. It introduces no backwards-incompatible changes. All valid DocBook 4.4 documents are also valid DocBook 4.5 documents.

The Committee decided to produce a DocBook V4.5, incorporating a few recent backwards-compatible changes, in order to publish DocBook as a Committee Draft and eventually as an OASIS Standard through the new process.

The DocBook Technical Committee welcomes bug reports and requests for enhancement (RFEs) from the user community. The current list of outstanding requests is available through the SourceForge tracker interface. This is also the preferred mechanism for submitting new requests. Old RFEs, from a previous legacy tracking system, are archived for reference.

2. Terminology

The key words must, must not, required, shall, shall not, should, should not, recommended, may, and optional in this Committee Specification are to be interpreted as described in [RFC 2119]. Note that for reasons of style, these words are not capitalized in this document.

3. The DocBook Document Type V4.5

The DocBook document type is distributed for XML and SGML from the DocBook site at OASIS. It is also available in RELAX NG and W3C XML Schema formats. The DocBook site is mirrored on

3.1. Changes in DocBook V4.5CR3

There are no backwards-incompatible changes in this release.

Version 4.5CR3 contains two small bug fixes to the SGML version of the DTD: the xml:lang attribute no longer appears on the HTML table elements (it was present erroneously, the xml:* attributes are suppressed in the SGML DTD) and markup minimization flags have been added to a few elements where they were missing. With these changes, the SGML DTD is once again consistent with the DocBook SGML declaration.

3.2. Changes in DocBook V4.5CR2

There are no backwards-incompatible changes in this release.

Version 4.5CR2 contains one small bug-fix applied after the Committee Specification was approved: the citebiblioid element is now allowed everywhere that the other citation elements are allowed. It had been accidentally excluded from some inline contexts in 4.5CR1.

3.3. Changes in the Public Review Draft of DocBook V4.5

There are no technical changes in this release.

3.4. Changes in DocBook V4.5CR1

There are no backwards-incompatible changes in this release.

Each of the changes made between DocBook V4.5b1 and DocBook V4.5CR1 is summarized here. For complete details, consult the individual RFEs and the meeting minutes.

There are no technical changes in DocBook V4.5CR1.

3.5. Changes in DocBook V4.5b1

There are no backwards-incompatible changes in this release.

Each of the changes made between DocBook V4.4 and DocBook V4.5b1 is summarized here. For complete details, consult the individual RFEs and the meeting minutes.

3.5.1. Bug Fixes

  • None.

3.5.2. Enhancements

4. Release Notes

XML validation technologies have evolved rapidly in the last few years. The Technical Committee is exploring the possibility of using RELAX NG as the principal validation technology for DocBook V5.0. The move to RELAX NG will also cause some one time backward-incompatible changes which are not listed in this specifcation.

A. The DocBook Media Type

This appendix registers a new MIME media type, "application/docbook+xml".

1. Registration of MIME media type application/docbook+xml

MIME media type name:


MIME subtype name:


Required parameters:


Optional parameters:

This parameter has identical semantics to the charset parameter of the application/xml media type as specified in [RFC 3023] or its successors.

Encoding considerations:

By virtue of DocBook XML content being XML, it has the same considerations when sent as "application/docbook+xml" as does XML. See [RFC 3023], Section 3.2.

Security considerations:

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

Interoperability considerations:


Published specification:

This media type registration is for DocBook documents as described by [DocBook: TDG].

Applications which use this media type:

There is no experimental, vendor specific, or personal tree predecessor to "application/docbook+xml", 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.

Additional information:
Magic number(s):

There is no single initial octet sequence that is always present in DocBook documents.

File extension(s):

DocBook documents are most often identified with the extension ".xml".

Macintosh File Type Code(s):


Person & email address to contact for further information:

Norman Walsh, .

Intended usage:


Author/Change controller:

The DocBook specification is a work product of the DocBook Technical Committee at OASIS.

2. Fragment Identifiers

For documents labeled as "application/docbook+xml", the fragment identifier notation is exactly that for "application/xml", as specified in [RFC 3023] or its successors.

B. OASIS DocBook Technical Committee (Non-Normative)

The following individuals were members of the committee during the formulation of this Committee Specification:

  • Adam Di Carlo

  • Steve Cogorno

  • Gary Cornelius

  • Dick Hamilton

  • Nancy Harrison

  • Scott Hudson

  • Paul Grosso

  • Mark Johnson

  • Jirka Kosek

  • Larry Rowland

  • Michael Smith

  • Robert Stayton, Secretary

  • Norman Walsh, Chair, Editor

C. Notices

Copyright © The Organization for the Advancement of Structured Information Standards [OASIS] 2001, 2002, 2003, 2004, 2005, 2006. All Rights Reserved.

OASIS takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on OASIS's procedures with respect to rights in OASIS specifications can be found at the OASIS website. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification, can be obtained from the OASIS Executive Director.

OASIS invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to implement this specification. Please address the information to the OASIS Executive Director.

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to OASIS, except as needed for the purpose of developing OASIS specifications, in which case the procedures for copyrights defined in the OASIS Intellectual Property Rights document must be followed, or as required to translate it into languages other than English.

The limited permissions granted above are perpetual and will not be revoked by OASIS or its successors or assigns.


OASIS has been notified of intellectual property rights claimed in regard to some or all of the contents of this specification. For more information consult the online list of claimed rights.

D. Intellectual Property Rights

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 DocBook web page (

E. Revision History

Revision Committee Specification CR3 2 June 2006
Revision Committee Specification CR2 14 April 2006
Revision Committee Specification CR1 09 March 2006
Revision Public Review Draft 28 July 2005
Revision Working Draft CR1 29 June 2005
Revision Working Draft b1 05 May 2005



[SGML] JTC 1, SC 34. ISO 8879:1986 Information processing -- Text and office systems -- Standard Generalized Markup Language (SGML). 1986.

[XML] Tim Bray, Jean Paoli, C. M. Sperberg-McQueen, et. al., editors. Extensible Markup Language (XML) 1.0 (Third Edition). World Wide Web Consortium, 04 Feb 2004.

[RFC 2119] IETF (Internet Engineering Task Force). RFC 2119: Key words for use in RFCs to Indicate Requirement Levels. S. Bradner. 1997.

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

[DocBook: TDG] Norman Walsh and Leonard Meullner. DocBook: The Definitive Guide. O’Reilly & Associates, 1999.