Walmsley - Definitive XML Schema

Second Edition

Priscilla Walmsley

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Titles in this series are produced using XML, SGML, and/or XSL. XSL-FO documents are rendered into PDF by the XEP Rendering Engine from RenderX: www.renderx.com.

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Library of Congress Cataloging-in-Publication Data is on file

Copyright 2013 Pearson Education, Inc.

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ISBN-13: 978-0-132-88672-7
ISBN-10: 0-132-88672-3
Text printed in the United States on recycled paper at Edwards Brothers Malloy in Ann Arbor, MI.
First printing: September 2012

Editor-in-Chief: Mark L. Taub
Managing Editor: Kristy Hart
Book Packager: Alina Kirsanova
Cover Designer: Alan Clements

The Charles F. Goldfarb Definitive XML Series

Priscilla Walmsley

Definitive XML Schema Second Edition

Charles F. Goldfarb and Paul Prescod

Charles F. Goldfarbs XML Handbook Fifth Edition

Rick Jelliffe

The XML and SGML Cookbook: Recipes for Structured Information

Charles F. Goldfarb, Steve Pepper, and Chet Ensign

SGML Buyers Guide: Choosing the Right XML and SGML Products and Services

G. Ken Holman

Definitive XSL-FO

Definitive XSLT and XPath

Bob DuCharme

XML: The Annotated Specification

SGML CD

Truly Donovan

Industrial-Strength SGML: An Introduction to Enterprise Publishing

Lars Marius Garshol

Definitive XML Application Development

JP Morgenthal with Bill la Forge

Enterprise Application Integration with XML and Java

Michael Leventhal, David Lewis, and Matthew Fuchs

Designing XML Internet Applications

Adam Hocek and David Cuddihy

Definitive VoiceXML

Dmitry Kirsanov

XSLT 2.0 Web Development

Yuri Rubinsky and Murray Maloney

SGML on the Web: Small Steps Beyond HTML

David Megginson

Structuring XML Documents

Sean McGrath

XML Processing with Python

XML by Example: Building E-commerce Applications

ParseMe.1st: SGML for Software Developers

Chet Ensign

$GML: The Billion Dollar Secret

Ron Turner, Tim Douglass, and Audrey Turner

ReadMe.1st: SGML for Writers and Editors

Charles F. Goldfarb and Priscilla Walmsley

XML in Office 2003: Information Sharing with Desktop XML

Michael Floyd

Building Web Sites with XML

Fredrick Thomas Martin

TOP SECRET Intranet: How U.S. Intelligence Built IntelinkThe Worlds Largest, Most Secure Network

J. Craig Cleaveland

Program Generators with XML and Java

Charles F. Goldfarb is the father of XML technology. He invented SGML, the Standard Generalized Markup Language on which both XML and HTML are based. You can find him on the Web at: www.xmlbooks.com.

The rebus is an ancient literary tradition, dating from 16th century Picardy, and is especially appropriate to a series involving fine distinctions between markup and text, metadata and data. The logo is a rebus incorporating the series name within a stylized XML comment declaration.

To Doug, my SH

classic(adjective)
judged over a period of time to be important and of the highest quality:

a classic novel
a classic car

Neither this definition, nor any of the leading dictionary definitions, has a usage example anything like:

a classic work on high-tech software

After all, it is a rare book on software that even survives long enough to be judged over a period of time.

Nevertheless, Definitive XML Schema satisfies every definition of classic. It is one of the elite few software books that have been in print continuously for over ten years, and an essential trustworthy guide for tens of thousands of readers.

This Second Edition continues to be an essential and trustworthy classic:

Essential because in the last ten years XML has become the accepted standard for data interchange, and XML Schema 1.0 is largely responsible. Now version 1.1 has extended the ability to specify and validate document data, to a degree previously possible only for databases. These updates are covered in this book by extensive revisionsthe most significant 250 of which are flagged in the text and table of contents. Hundreds more unflagged revisions reflect W3C corrections of XML Schema errata, and ten years of evolving best practices.

Trustworthy because it is both authoritative and accurate.

The author(ity), Priscilla Walmsley, is a noted consultant who has been using XML Schema ever since she helped develop it as a member of the W3C XML Schema Group. She personally devised many of the current best practices described in this book. Priscilla is the Editor of the W3C XML Schema Primer, Second Edition.

Accuracy was preserved by using the same XML-based production system that was used in 2002, operated by the same team of XML experts who read and thoroughly understood the book. Priscillas original XML source (in which she had personally tagged the version 1.1 revisions) was used throughout production. Dmitry Kirsanov copy-edited and proofed it, while Alina Kirsanova prepared the index, coded the XSL transformations, and generated the camera-ready PDFs.