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<p><a href="http://www.w3.org/"><img src=
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<h1>Discussion of Alternative Schema Languages and Type System
Support in WSDL 2.0</h1>
<h2 id="h2-title">W3C Working Group Note 17 August 2005</h2>
<dl>
<dt id="dt-this-version">This version:</dt>
<dd><a href=
"http://www.w3.org/TR/2005/NOTE-wsdl20-altschemalangs-20050817">http://www.w3.org/TR/2005/NOTE-wsdl20-altschemalangs-20050817</a></dd>
<dt>Latest version:</dt>
<dd><a href=
"http://www.w3.org/TR/wsdl20-altschemalangs">http://www.w3.org/TR/wsdl20-altschemalangs</a></dd>
<dt>Editors:</dt>
<dd>Amelia A. Lewis, TIBCO Software, Inc.</dd>
<dd>Bijan Parsia, Maryland Information and Network Dynamics
Laboratory at the University of Maryland at College Park</dd>
</dl>
<p>This document is also available in these non-normative formats:
<a href="wsdl20-altschemalangs.pdf">PDF</a>, <a href=
"wsdl20-altschemalangs.ps">PostScript</a>, <a href=
"wsdl20-altschemalangs.xml">XML</a>, and&nbsp;<a href=
"wsdl20-altschemalangs.txt">plain text</a>.</p>
<p class="copyright"><a href=
"http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a>&nbsp;©&nbsp;2005&nbsp;<a href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>®</sup>
(<a href="http://www.csail.mit.edu/"><acronym title=
"Massachusetts Institute of Technology">MIT</acronym></a>, <a href=
"http://www.ercim.org/"><acronym title=
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<a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved.
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use</a> rules apply.</p>
</div>
<hr />
<div>
<h2><a name="abstract" id="abstract">Abstract</a></h2>
<p>This document captures the result of discussions by the Web
Services Description Working Group regarding WSDL 2.0 type system
extensibilty at the time of its publication. The Working Group
normatively defines the use of XML Schema 1.0 as a type system in
the WSDL 2.0 Core specification. This document sketches out the
basics of extensions for Document Type Definitions (DTDs) and Relax
NG.</p>
</div>
<div>
<h2><a name="status" id="status">Status of this Document</a></h2>
<p><em>This section describes the status of this document at the
time of its publication. Other documents may supersede this
document. A list of current W3C publications and the latest
revision of this technical report can be found in the <a href=
"http://www.w3.org/TR/">W3C technical reports index</a> at
http://www.w3.org/TR/.</em></p>
<p>This document is a <a href=
"http://www.w3.org/2004/02/Process-20040205/tr.html#q74">W3C
Working Group Note</a>. It has been produced by the <a href=
"http://www.w3.org/2002/ws/desc/">Web Services Description Working
Group</a>, which is part of the <a href=
"http://www.w3.org/2002/ws/Activity">Web Services Activity</a>.</p>
<p>The material in this note was previously published as an
Appendix of the <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050510">Web Services
Description Language (WSDL) 2.0: Core Language Last Call</a>
specification. In response to Last Call comments, the Working Group
agreed to remove this material from that specification and publish
it separately as a Working Group Note. Current versions of <a href=
"http://www.w3.org/TR/wsdl20">WSDL 2.0 Core</a> no longer contain
this material. This publication differs from the previous material
in that it also includes some expanded discussion of issues that
should be given consideration by type system extension
designers.</p>
<p>No further work on this topic is planned at this point. Errors
in this document can be reported to the public <a href=
"mailto:public-ws-desc-comments@w3.org">public-ws-desc-comments@w3.org</a>
mailing list (<a href=
"http://lists.w3.org/Archives/Public/public-ws-desc-comments/">public
archive</a>).</p>
<p>Publication as a Working Group Note does not imply endorsement
by the W3C Membership. This is a draft document and may be updated,
replaced or obsoleted by other documents at any time. It is
inappropriate to cite this document as other than work in
progress.</p>
</div>
<hr />
<div class="toc">
<h2><a name="shortcontents" id="shortcontents">Short Table of
Contents</a></h2>
<p class="toc">1. <a href="#intro">Introduction</a><br />
2. <a href="#multipleschemalangs">Issues facing multiple schema
languages/type systems</a><br />
3. <a href="#examples">Examples of Specifications of Extension
Elements for Alternative Schema Language Support</a><br />
A. <a href="#References">References</a><br />
B. <a href="#acknowledgments">Acknowledgements</a>
(Non-Normative)<br /></p>
</div>
<hr />
<div class="toc">
<h2><a name="contents" id="contents">Table of Contents</a></h2>
<p class="toc">1. <a href="#intro">Introduction</a><br />
2. <a href="#multipleschemalangs">Issues facing multiple schema
languages/type systems</a><br />
3. <a href="#examples">Examples of Specifications of Extension
Elements for Alternative Schema Language Support</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;3.1 <a href="#dtd">DTD</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.1.1 <a href=
"#dtd-namespaceaii">namespace attribute information item</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.1.2 <a href=
"#dtd-locationaii">location attribute information item</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.1.3 <a href=
"#dtd-ref">References to Element Definitions</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;3.2 <a href="#relax">RELAX NG</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.1 <a href=
"#import-relax">Importing RELAX NG</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.1.1
<a href="#relax-import-nsaii">ns attribute information
item</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.1.2
<a href="#relax-import-hrefaii">href attribute information
item</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.2 <a href=
"#relax-embed">Embedding RELAX NG</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.2.1
<a href="#relax-embed-nsaii">ns attribute information
item</a><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2.3 <a href=
"#relax-ref">References to Element Declarations</a><br /></p>
<h3><a name="appendix" id="appendix">Appendices</a></h3>
<p class="toc">A. <a href="#References">References</a><br />
B. <a href="#acknowledgments">Acknowledgements</a>
(Non-Normative)<br /></p>
</div>
<hr />
<div class="body">
<div class="div1">
<h2><a name="intro" id="intro"></a>1. Introduction</h2>
<p>WSDL 2.0: Core Language [<cite><a href="#WSDL">WSDL 2.0
Core</a></cite>] describes Web Service interaction in terms of
exchanges of typed messages. WSDL only provides general support for
type systems based on the XML Infoset [<cite><a href=
"#XMLInfoSet">XML Information Set</a></cite>] and specific support
for the W3C XML Schema Description Language [<cite><a href=
"#XMLSchemaP1">XML Schema: Structures</a></cite>]. Describing
messages with WSDL using schema languages other than XML Schema or
non-XML Infoset type systems requires extending the WSDL component
model. While the Web Services Description Working Group has not
defined any such extensions, there were discussions in the Working
Group about how those extensions might be defined and used. This
document is the result of those disucussions and captures part of
the Working Group's thinking about schema language and type system
extensibilty at the time of its publication.</p>
</div>
<div class="div1">
<h2><a name="multipleschemalangs" id="multipleschemalangs"></a>2.
Issues facing multiple schema languages/type systems</h2>
<p>Without the use of an extension, a WSDL document can only use a
single type system, XML Schema. If extensions are defined to
support alternative schema languages or non-XML type systems, then
issues regarding the <em>mixing</em> of type systems in a single
document arise. Part 1 does <em>not</em> define the behavior of
mixed type system documents, so it is incumbent on extension
authors to do so.</p>
<p>For example, suppose a WSDL author used a extension supporting
Relax NG alongside the native support for XML Schema. Further
suppose that there is an element component which has a definition
in both the referenced XML Schema and Relax NG schema. There are
several possibilities for interpreting such a document:</p>
<ul>
<li>
<p>Multiple definitions in distinct type systems is always an
error</p>
</li>
<li>
<p>Multiple definitions must be in some sense equivalent, for
example, if XML Schema type and an Relax NG production validate
exactly the same set of Infoset fragments, otherwise, an error</p>
</li>
<li>
<p>Multiple definitions are legal, and are interpreted as a union
type constraint</p>
</li>
</ul>
<p>The last interpretation suggests a further general possibility:
being able to define a union type (or other compound type) that
spans distinct type systems (and, to further generalize, where the
unioned types had distinct QName identifiers). The <a href=
"http://www.w3.org/2001/sw/DataAccess/">Data Access Working
Group</a> had a use case wherein their return message could either
be in <a href=
"http://www.w3.org/TR/rdf-syntax-grammar/">RDF/XML</a>, which
cannot have an interesting XML Schema but does have an interesting
Relax NG schema, and their <a href=
"http://www.w3.org/TR/rdf-sparql-XMLres/">other results format</a>,
which they would prefer to specify with an XML Schema. This example
is little artificial, as the Data Access Working Group could easily
describe the entire results format in Relax NG.</p>
<p>The first interpretation is most in the spirit of WSDL and was
strongly preferred by the Working Group. Since WSDL extensibility
points are generally quite unrestricted, the Working Group did not
try to enforce the first option, but the general belief of the
Working Group was that the other options were confusing and
unwise.</p>
</div>
<div class="div1">
<h2><a name="examples" id="examples"></a>3. Examples of
Specifications of Extension Elements for Alternative Schema
Language Support</h2>
<p>This section contains two examples of specifications of
extension elements for alternative schema language support. Please
note that those examples did not receive any implementation
testing.</p>
<div class="div2">
<h3><a name="dtd" id="dtd"></a>3.1 DTD</h3>
<p>A Document Type Definition (DTD) as defined in [<cite><a href=
"#XML10">XML 1.0</a></cite>] may be used as the schema language for
WSDL. It may not be embedded; it must be imported. A namespace must
be assigned. DTD types appear in the {<a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#property-Description.elementdeclarations">element
declarations</a>} property of the <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-Description">
Description</a> component and may be referenced from the
<code>wsdl:input</code> , <code>wsdl:output</code> and
<code>wsdl:fault</code> elements using the <code>element</code>
<em>attribute information item</em>.</p>
<p>The prefix, dtd, used throughout the following is mapped to the
namespace URI "http://www.w3.org/2005/08/wsdl/dtd-import".</p>
<p>The <code>dtd:import</code> <em>element information item</em>
references an external Document Type Definition, and has the
following Infoset properties:</p>
<ul>
<li>
<p>A [local name] of import.</p>
</li>
<li>
<p>A [namespace name] of
"http://www.w3.org/2005/08/wsdl/dtd-import".</p>
</li>
<li>
<p>One or two <em>attribute information item</em>s, as follows:</p>
<ul>
<li>
<p>A REQUIRED <code>namespace</code> <em>attribute information
item</em> as described below.</p>
</li>
<li>
<p>An OPTIONAL <code>location</code> <em>attribute information
item</em> as described below.</p>
</li>
</ul>
</li>
</ul>
<div class="div3">
<h4><a name="dtd-namespaceaii" id="dtd-namespaceaii"></a>3.1.1
<code>namespace</code> <em>attribute information item</em></h4>
<p>The <code>namespace</code> <em>attribute information item</em>
sets the namespace to be used with all imported element definitions
described in the DTD. It has the following Infoset properties:</p>
<ul>
<li>
<p>A [local name] of namespace.</p>
</li>
<li>
<p>A [namespace name] which has no value.</p>
</li>
</ul>
<p>The type of the <code>namespace</code> <em>attribute information
item</em> is <em>xs:anyURI</em>.</p>
<p>The WSDL author should ensure that a prefix is associated with
the namespace at the proper scope (probably document scope).</p>
</div>
<div class="div3">
<h4><a name="dtd-locationaii" id="dtd-locationaii"></a>3.1.2
<code>location</code> <em>attribute information item</em></h4>
<p>The <code>location</code> <em>attribute information item</em>,
if present, provides a hint to the processor as to where the DTD
may be located. Caching and cataloging technologies may provide
better information than this hint. The <code>location</code>
<em>attribute information item</em> has the following Infoset
properties:</p>
<ul>
<li>
<p>A [local name] of location.</p>
</li>
<li>
<p>A [namespace name] which has no value.</p>
</li>
</ul>
<p>The type of the <code>location</code> <em>attribute information
item</em> is <em>xs:anyURI</em>.</p>
</div>
<div class="div3">
<h4><a name="dtd-ref" id="dtd-ref"></a>3.1.3 References to Element
Definitions</h4>
<p>The <code>element</code> <em>attribute information item</em>
MUST be used when referring to an element definition
(&lt;!ELEMENT&gt;) from a <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-InterfaceMessageReference">
Interface Message Reference</a> component; referring to an element
definition from a <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-InterfaceFault">
Interface Fault</a> component is similar. The value of the element
definition MUST correspond to the content of the
<code>namespace</code> <em>attribute information item</em> of the
<code>dtd:import</code> <em>element information item</em>. The
local name part must correspond to an element defined in the
DTD.</p>
<p>Note that this pattern does not attempt to make DTDs
namespace-aware. It applies namespaces externally, in the import
phase.</p>
</div>
</div>
<div class="div2">
<h3><a name="relax" id="relax"></a>3.2 RELAX NG</h3>
<p>A RELAX NG [<cite><a href="#RelaxNG">Relax NG</a></cite>] schema
may be used as the schema language for WSDL. It may be embedded or
imported; import is preferred. A namespace must be specified; if an
imported schema specifies one, then the [actual value] of the
<code>namespace</code> <em>attribute information item</em> in the
<code>import</code> <em>element information item</em> must match
the specified namespace. RELAX NG provides both type definitions
and element declarations, the latter appears in the {<a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#property-Description.elementdeclarations">element
declarations</a>} property of <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-Description">
Description</a> component respectively. The following discussion
supplies the prefix rng which is mapped to the URI
"http://www.relaxng.org/ns/structure/1.0".</p>
<div class="div3">
<h4><a name="import-relax" id="import-relax"></a>3.2.1 Importing
RELAX NG</h4>
<p>Importing a RELAX NG schema uses the rng:include mechanism
defined by RNG, with restrictions on its syntax and semantics. A
child <em>element information item</em> of the <code>types</code>
<em>element information item</em> is defined with the Infoset
properties as follows:</p>
<ul>
<li>
<p>A [local name] of include.</p>
</li>
<li>
<p>A [namespace name] of
"http://www.relaxng.org/ns/structure/1.0".</p>
</li>
<li>
<p>Two <em>attribute information item</em>s as follows:</p>
<ul>
<li>
<p>A REQUIRED <code>ns</code> <em>attribute information item</em>
as described below.</p>
</li>
<li>
<p>An OPTIONAL <code>href</code> <em>attribute information
item</em> as described below.</p>
</li>
<li>
<p>Additional <em>attribute information item</em>s as defined by
the RNG specification.</p>
</li>
</ul>
</li>
</ul>
<p>Note that WSDL restricts the <code>rng:include</code>
<em>element information item</em> to be empty. That is, it cannot
redefine <code>rng:start</code> and <code>rng:define</code>
<em>element information item</em>s; it may be used solely to import
a schema.</p>
<div class="div4">
<h5><a name="relax-import-nsaii" id=
"relax-import-nsaii"></a>3.2.1.1 <code>ns</code> <em>attribute
information item</em></h5>
<p>The <code>ns</code> <em>attribute information item</em> defines
the namespace of the type and element definitions imported from the
referenced schema. If the referenced schema contains an
<code>ns</code> <em>attribute information item</em> on its
<code>grammar</code> <em>element information item</em>, then the
values of these two <em>attribute information item</em>s must be
identical. If the imported grammar does not have an <code>ns</code>
<em>attribute information item</em> then the namespace specified
here is applied to all components of the schema as if it did
contain such an <em>attribute information item</em>. The
<code>ns</code> <em>attribute information item</em> contains the
following Infoset properties:</p>
<ul>
<li>
<p>A [local name] of ns.</p>
</li>
<li>
<p>A [namespace name] which has no value.</p>
</li>
</ul>
<p>The type of the <code>ns</code> <em>attribute information
item</em> is <em>xs:anyURI</em>.</p>
</div>
<div class="div4">
<h5><a name="relax-import-hrefaii" id=
"relax-import-hrefaii"></a>3.2.1.2 <code>href</code> <em>attribute
information item</em></h5>
<p>The <code>href</code> <em>attribute information item</em> must
be present, according to the rules of the RNG specification.
However, WSDL allows it to be empty, and considers it only a hint.
Caching and cataloging technologies may provide better information
that this hint. The <code>href</code> <em>attribute information
item</em> has the following Infoset properties:</p>
<ul>
<li>
<p>A [local name] of href.</p>
</li>
<li>
<p>A [namespace name] which has no value.</p>
</li>
</ul>
<p>The type of the <code>href</code> <em>attribute information
item</em> is <em>xs:anyURI</em>.</p>
</div>
</div>
<div class="div3">
<h4><a name="relax-embed" id="relax-embed"></a>3.2.2 Embedding
RELAX NG</h4>
<p>Embedding an RNG schema uses the existing top-level
<code>rng:grammar</code> <em>element information item</em>. It may
be viewed as simply cutting and pasting an existing, stand-alone
schema to a location inside the <code>wsdl:types</code> <em>element
information item</em>. The <code>rng:grammar</code> <em>element
information item</em> has the following Infoset properties:</p>
<ul>
<li>
<p>A [local name] of grammar.</p>
</li>
<li>
<p>A [namespace name] of
"http://www.relaxng.org/ns/structure/1.0".</p>
</li>
<li>
<p>A REQUIRED <code>ns</code> <em>attribute information item</em>s
as described below.</p>
</li>
<li>
<p>Additional <em>attribute information item</em>s as specified for
the <code>rng:grammar</code> <em>element information item</em> in
the RNG specification.</p>
</li>
<li>
<p>Child <em>element information item</em>s as specified for the
<code>rng:grammar</code> <em>element information item</em> in the
RNG specification.</p>
</li>
</ul>
<div class="div4">
<h5><a name="relax-embed-nsaii" id="relax-embed-nsaii"></a>3.2.2.1
<code>ns</code> <em>attribute information item</em></h5>
<p>The <code>ns</code> <em>attribute information item</em> defines
the namespace of the type and element definitions embedded in this
schema. WSDL modifies the RNG definition of the
<code>rng:grammar</code> <em>element information item</em> to make
this <em>attribute information item</em> required. The
<code>ns</code> <em>attribute information item</em> has the
following Infoset properties:</p>
<ul>
<li>
<p>A [local name] of ns.</p>
</li>
<li>
<p>A [namespace name] which has no value.</p>
</li>
</ul>
<p>The type of the <code>ns</code> <em>attribute information
item</em> is <em>xs:anyURI</em>.</p>
</div>
</div>
<div class="div3">
<h4><a name="relax-ref" id="relax-ref"></a>3.2.3 References to
Element Declarations</h4>
<p>Whether embedded or imported, the element definitions present in
a schema may be referenced from a <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-InterfaceMessageReference">
Interface Message Reference</a> or <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-InterfaceFault">
Interface Fault</a> component.</p>
<p>A named rng:define definition MUST NOT be referenced from the
<a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-InterfaceMessageReference">
Interface Message Reference</a> or <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-InterfaceFault">
Interface Fault</a> components.</p>
<p>A named Relax NG element declaration MAY be referenced from a
<a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-InterfaceMessageReference">
Interface Message Reference</a> or <a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803#component-InterfaceFault">
Interface Fault</a> component. The QName is constructed from the
namespace (<code>ns</code> <em>attribute information item</em>) of
the schema and the content of the <code>name</code> <em>attribute
information item</em> of the <code>element</code> <em>element
information item</em> An <code>element</code> <em>attribute
information item</em> MUST NOT be used to refer to an
<code>rng:define</code> <em>element information item</em>.</p>
</div>
</div>
</div>
</div>
<div class="back">
<div class="div1">
<h2><a name="References" id="References"></a>A. References</h2>
<dl>
<dt class="label"><a name="RelaxNG" id="RelaxNG"></a>[Relax
NG]</dt>
<dd><cite><a href="http://www.relaxng.org/spec-20011203.html">RELAX
NG Specification</a></cite>, J. Clark, MURATA Makoto, editors.
OASIS Committee Specification, 3 December 2001.</dd>
<dt class="label"><a name="WSDL" id="WSDL"></a>[WSDL 2.0 Core]</dt>
<dd><cite><a href=
"http://www.w3.org/TR/2005/WD-wsdl20-20050803">Web Services
Description Language (WSDL) Version 2.0 Part 1: Core
Language</a></cite>, R. Chinnici, J-J. Moreau, A. Ryman, S.
Weerawarana, Editors. World Wide Web Consortium, 3 August 2005.
This version of the Web Services Description Language Version 2.0
Core specification is http://www.w3.org/TR/2005/WD-wsdl20-20050803.
The <a href="http://www.w3.org/TR/wsdl20">latest version of "Web
Services Description Language (WSDL) Version 2.0 Part 1: Core
Language"</a> is available at http://www.w3.org/TR/wsdl20.</dd>
<dt class="label"><a name="XML10" id="XML10"></a>[XML 1.0]</dt>
<dd><cite><a href=
"http://www.w3.org/TR/2004/REC-xml-20040204/">Extensible Markup
Language (XML) 1.0 (Third Edition)</a></cite>, T. Bray, J. Paoli,
C. M. Sperberg-McQueen, E. Maler, and F. Yergeau, Editors. World
Wide Web Consortium, 4 February 2004. This version of the XML 1.0
Recommendation is http://www.w3.org/TR/2004/REC-xml-20040204/. The
<a href="http://www.w3.org/TR/REC-xml">latest version of
"Extensible Markup Language (XML) 1.0"</a> is available at
http://www.w3.org/TR/REC-xml.</dd>
<dt class="label"><a name="XMLInfoSet" id="XMLInfoSet"></a>[XML
Information Set]</dt>
<dd><cite><a href=
"http://www.w3.org/TR/2004/REC-xml-infoset-20040204">XML
Information Set (Second Edition)</a></cite>, J. Cowan and R. Tobin,
Editors. World Wide Web Consortium, 4 February 2004. This version
of the XML Information Set Recommendation is
http://www.w3.org/TR/2004/REC-xml-infoset-20040204. The <a href=
"http://www.w3.org/TR/xml-infoset">latest version of "XML
Information Set"</a> is available at
http://www.w3.org/TR/xml-infoset.</dd>
<dt class="label"><a name="XMLSchemaP1" id="XMLSchemaP1"></a>[XML
Schema: Structures]</dt>
<dd><cite><a href=
"http://www.w3.org/TR/2004/REC-xmlschema-1-20041028/">XML Schema
Part 1: Structures (Second Edition)</a></cite>, H. Thompson, D.
Beech, M. Maloney, and N. Mendelsohn, Editors. World Wide Web
Consortium, 28 October 2004. This version of the XML Schema Part 1
Recommendation is
http://www.w3.org/TR/2004/REC-xmlschema-1-20041028. The <a href=
"http://www.w3.org/TR/xmlschema-1/">latest version of "XML Schema
Part 1: Structures"</a> is available at
http://www.w3.org/TR/xmlschema-1.</dd>
</dl>
</div>
<div class="div1">
<h2><a name="acknowledgments" id="acknowledgments"></a>B.
Acknowledgements (Non-Normative)</h2>
<p>This document is the work of the <a href=
"http://www.w3.org/2002/ws/desc/">W3C Web Service Description
Working Group</a>.</p>
<p>Members of the Working Group are (at the time of writing, and by
alphabetical order): Allen Brookes (Rogue Wave Softwave), Dave
Chappell (Sonic Software), Helen Chen (Agfa-Gevaert N. V.), Roberto
Chinnici (Sun Microsystems), Kendall Clark (University of
Maryland), Ugo Corda (SeeBeyond), Glen Daniels (Sonic Software),
Paul Downey (British Telecommunications), Youenn Fablet (Canon),
Hugo Haas (W3C), Tom Jordahl (Macromedia), Anish Karmarkar (Oracle
Corporation), Jacek Kopecky (DERI Innsbruck at the
Leopold-Franzens-Universität Innsbruck, Austria), Amelia Lewis
(TIBCO Software, Inc.), Michael Liddy (Education.au Ltd.), Kevin
Canyang Liu (SAP AG), Jonathan Marsh (Microsoft Corporation),
Josephine Micallef (SAIC - Telcordia Technologies), Jeff
Mischkinsky (Oracle Corporation), Dale Moberg (Cyclone Commerce),
Jean-Jacques Moreau (Canon), Mark Nottingham (BEA Systems, Inc.),
David Orchard (BEA Systems, Inc.), Bijan Parsia (University of
Maryland), Tony Rogers (Computer Associates), Arthur Ryman (IBM),
Adi Sakala (IONA Technologies), Asir Vedamuthu (Microsoft
Corporation), Sanjiva Weerawarana (Independent), Ümit Yalçınalp
(SAP AG).</p>
<p>Previous members were: Lily Liu (webMethods, Inc.), Don Wright
(Lexmark), Joyce Yang (Oracle Corporation), Daniel Schutzer
(Citigroup), Dave Solo (Citigroup), Stefano Pogliani (Sun
Microsystems), William Stumbo (Xerox), Stephen White (SeeBeyond),
Barbara Zengler (DaimlerChrysler Research and Technology), Tim
Finin (University of Maryland), Laurent De Teneuille (L'Echangeur),
Johan Pauhlsson (L'Echangeur), Mark Jones (AT&amp;T), Steve Lind
(AT&amp;T), Sandra Swearingen (U.S. Department of Defense, U.S. Air
Force), Philippe Le Hégaret (W3C), Jim Hendler (University of
Maryland), Dietmar Gaertner (Software AG), Michael Champion
(Software AG), Don Mullen (TIBCO Software, Inc.), Steve Graham
(Global Grid Forum), Steve Tuecke (Global Grid Forum), Michael
Mahan (Nokia), Bryan Thompson (Hicks &amp; Associates), Ingo Melzer
(DaimlerChrysler Research and Technology), Sandeep Kumar (Cisco
Systems), Alan Davies (SeeBeyond), Jacek Kopecky (Systinet), Mike
Ballantyne (Electronic Data Systems), Mike Davoren (W. W.
Grainger), Dan Kulp (IONA Technologies), Mike McHugh (W. W.
Grainger), Michael Mealling (Verisign), Waqar Sadiq (Electronic
Data Systems), Yaron Goland (BEA Systems, Inc.), Ümit Yalçınalp
(Oracle Corporation), Peter Madziak (Agfa-Gevaert N. V.), Jeffrey
Schlimmer (Microsoft Corporation), Hao He (The Thomson
Corporation), Erik Ackerman (Lexmark), Jerry Thrasher (Lexmark),
Prasad Yendluri (webMethods, Inc.), William Vambenepe
(Hewlett-Packard Company), David Booth (W3C), Sanjiva Weerawarana
(IBM), Charlton Barreto (webMethods, Inc.), Asir Vedamuthu
(webMethods, Inc.), Igor Sedukhin (Computer Associates), Martin
Gudgin (Microsoft Corporation).</p>
<p>The people who have contributed to <a href=
"http://lists.w3.org/Archives/Public/www-ws-desc/">discussions on
www-ws-desc@w3.org</a> are also gratefully acknowledged.</p>
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