Basic XML Schema Patterns for Databinding Version 1.0

1. Introduction

A databinding tool generates a mapping between [XML 1.0] documents which conform to an [XML Schema 1.0] schema and an internal data representation. For example, a Web services databinding tool may use [XML Schema 1.0] descriptions inside a [WSDL 2.0] or [WSDL 1.1] document to produce and consume [XML 1.0], [SOAP 1.2] and [SOAP 1.1] messages in terms of data structures in a programming language or data held inside a database.

[XML Schema 1.0] provides a wide variety of methods for describing the same [XML 1.0] structure. Conversely an abstract concept such as "null" may be represented in a wide variety of different ways using [XML Schema 1.0].

A representative collection of databinding implementations in common use has been used to provide an indication of the "state of the art". State of the art databinding implementations have displayed uneven and inconsistent support of the W3C [XML Schema 1.0] Recommendation resulting in impaired interoperability and a poor user experience of databinding tools:

rejecting valid [XML Schema 1.0] documents,
rejecting valid [XML 1.0] instance documents, and
making the content of valid [XML 1.0] instance documents unavailable in mapped data structures.

This specification provides a basic set of example [XML Schema 1.0] constructs and types in the form of concrete [XPath 2.0] expressions. These patterns are known to work well with state of the art databinding implementations.

Authors of [XML Schema 1.0] documents may find these patterns useful in providing a better user experience for consumers of their schemata using databinding tools. Whilst it is not possible to guarantee that schemata produced using these patterns will give a good user experience with the universal set of databinding tools, the patterns contained in this specification have been all been tested with a number of different tools covering a variety of different programming languages and environments.

Implementers of databinding tools may find these patterns useful to represent simple and common place data structures. Ensuring tools recognize at least these simple [XML Schema 1.0] patterns and present them in terms most appropriate to the specific language, database or environment will provide an improved user experience when using databinding tools. It is inappropriate to use this specification to constrain implementation of the [XML Schema 1.0] Recommendation.

1.1 Notational Conventions

All parts of this specification are normative, with the EXCEPTION of notes, examples, and sections explicitly marked as Non-Normative.

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this specification are to be interpreted as described in [RFC 2119].

Each [XML Schema 1.0] pattern is defined using a single [XPath 2.0] expression constraining one or more [XML Schema 1.0] items.

Each [XML Schema 1.0] pattern is identified using a unique and stable URI [RFC 3986].

Assertions about documents and implementations that are not enforced by the normative patterns are marked by a dagger symbol (†) at the end of a sentence. Each assertion has been assigned a unique and stable identifier. The assertion identifiers may be used by implementations of this specification for any purpose, such as error reporting. The assertions and their identifiers are summarized in section E. Assertion Summary.

1.2 Namespaces

This specification uses a number of namespace prefixes throughout; they are listed in Table 1-1. Note that the choice of any namespace prefix is arbitrary and not semantically significant (see [XML Namespaces]).

Table 1-1. Prefixes and Namespaces used in this specification
Prefix	Namespace
xs	http://www.w3.org/2001/XMLSchema
xsi	http://www.w3.org/2001/XMLSchema-instance
soap11	http://schemas.xmlsoap.org/soap/envelope/
soap12	http://www.w3.org/2003/05/soap-envelope
wsdl11	http://schemas.xmlsoap.org/wsdl/
wsdl20	http://www.w3.org/2005/08/wsdl
pat	http://www.w3.org/2002/ws/databinding/patterns/6/09/
ex	http://www.w3.org/2002/ws/databinding/examples/6/09/

1.3 Document Conformance

A document claiming conformance to this specification:

MUST use either the UTF-8 or UTF-16 [Unicode] encoding.^†
MAY include the [Unicode] Byte Order Mark (BOM).^†
MUST be a well-formed [XML 1.0] document^†
MUST conform to the [XML Schema 1.0] Recommendation^†
MUST only contain [XML 1.0] element nodes and attribute nodes which form a part of one or more complete patterns contained in this specification.^†
MAY contain additional [XML 1.0] comment nodes and processing instruction nodes.^†

1.4 Implementation Conformance

An implementation that claims conformance to this specification:

SHOULD be able to process any valid [XML Schema 1.0] document.^†
MUST be able to process any [XML Schema 1.0] document conforming to this specification^†
MUST produce a data model exposing all of the [XML 1.0] element node and attribute node content described by the originating [XML Schema 1.0] document.^†
MUST be able to consume any well-formed [XML 1.0] document which satisfies local-schema validity against the originating [XML Schema 1.0] document exposing all of the [XML 1.0] element node and attribute node content in the data model.^†
MUST be able to produce well-formed [XML 1.0] instance documents which satisfy local-schema validity against the originating [XML Schema 1.0] document containing values exposed in the data model.^†
MAY consume well-formed [XML 1.0] instance documents which do not satisfy local-schema validity against the originating [XML Schema 1.0] document.^†
MAY allow the production of well-formed [XML 1.0] instance documents containing values exposed in the data model which do not satisfy local-schema validity against the originating [XML Schema 1.0] document.^†

Describing the form of the data model provided by a databinding implementation is beyond the scope of this specification. For example, the unconstrained built-in numeric primitive types, xs:decimal, xs:integer, xs:negativeInteger, xs:positiveInteger, xs:nonNegativeInteger and xs:nonPositiveInteger, do not map directly to native types in many programming languages and are likely to be presented as a toolkit specific construct or more generalised ways, such as a 'string'.

Note that although the patterns contained in this document are defined using [XPath 2.0], there is no requirement for a conformant implementation to support [XPath 2.0].

2. Schema Patterns

This section defines the set of concrete [XML Schema 1.0] patterns which may appear inside a conformant document. A pattern definition includes the following information:

URI: A URI [RFC 3986] is provided to identify the pattern. The URI can be dereferenced to return informal documentation for the pattern including a list of examples and public schemas which exhibit the pattern.
XPath: A normative [XPath 2.0] expression returning a set of one or more XML element and attribute nodes. The [XPath 2.0] expression is located from an [XML Schema 1.0] element node which may be the document element, or an element contained inside an [XML 1.0] document such as [WSDL 2.0] description.
Examples: Optionally one or more non-normative [XML Schema 1.0] documents or fragments, followed by one or more valid instance document fragments.

A collection of patterns, including patterns beyond the scope of this specification, are available from http://www.w3.org/2002/ws/databinding/patterns/6/09/.

This document offers no additional semantics for the schema patterns presented beyond those specified by the [XML Schema 1.0] Recommendation.

2.1 Schema Element

The xs:schema element MAY be the document element, but MAY also appear within other descriptions such as a [WSDL 2.0] or [WSDL 1.1] document. ^†

2.1.1 TargetNamespace

An [XML 1.0] document exhibits the TargetNamespace pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/TargetNamespace when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.[@targetNamespace]/ (., @targetNamespace)

An [XML Schema 1.0] document conforming to this specification MUST define a targetNamespace whose value is an absolute URI. ^†

The following example [XML Schema 1.0] document [TargetNamespace] illustrates the use of the TargetNamespace pattern:

<xs:schematargetNamespace="http://www.w3.org/2002/ws/databinding/examples/6/09/" elementFormDefault="qualified">
  <xs:element name="targetNamespace" type="xs:string" />
</xs:schema>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [TargetNamespace01]:

  <ex:targetNamespace>foo</ex:targetNamespace>

2.1.2 QualifiedLocalElements

An [XML 1.0] document exhibits the QualifiedLocalElements pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/QualifiedLocalElements when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.[@elementFormDefault = 'qualified']/
(@elementFormDefault)

An [XML Schema 1.0] document conforming to this specification MUST namespace qualify all locally declared elements using a schema element elementFormDefault attribute value of qualified. ^†

The following example [XML Schema 1.0] document [QualifiedLocalElements] illustrates the use of the QualifiedLocalElements pattern:

<xs:schema targetNamespace="http://www.w3.org/2002/ws/databinding/examples/6/09/" elementFormDefault="qualified">
  <xs:element name="qualifiedLocalElements" type="xs:string" />
</xs:schema>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [QualifiedLocalElements01]:

  <qualifiedLocalElements>bar</qualifiedLocalElements>

2.1.3 UnqualifiedLocalAttributes

An [XML 1.0] document exhibits the UnqualifiedLocalAttributes pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/UnqualifiedLocalAttributes when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.[not(@attributeFormDefault) or @attributeFormDefault =
'unqualified']/ (., @attributeFormDefault)

The following example [XML Schema 1.0] document [UnqualifiedLocalAttributes] illustrates the use of the UnqualifiedLocalAttributes pattern:

<xs:schema targetNamespace="http://www.w3.org/2002/ws/databinding/examples/6/09/" attributeFormDefault="unqualified" elementFormDefault="qualified">
  <xs:element name="unqualifiedLocalAttributes" type="xs:string" />
</xs:schema>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [UnqualifiedLocalAttributes01]:

  <ex:unqualifiedLocalAttributes>foo</ex:unqualifiedLocalAttributes>

2.1.4 SchemaVersion

An [XML 1.0] document exhibits the SchemaVersion pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/SchemaVersion when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./@version

The following example [XML Schema 1.0] document [SchemaVersion] illustrates the use of the SchemaVersion pattern:

<xs:schema targetNamespace="http://www.w3.org/2002/ws/databinding/examples/6/09/" elementFormDefault="qualified" version="this is version 42">
  <xs:element name="schemaVersion" type="xs:string" />
</xs:schema>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [SchemaVersion01]:

  <ex:schemaVersion>foo</ex:schemaVersion>

2.1.5 FinalDefault

An [XML 1.0] document exhibits the FinalDefault pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/FinalDefault when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./@finalDefault

The following example [XML Schema 1.0] document [FinalDefault] illustrates the use of the FinalDefault pattern:

<xs:schema targetNamespace="http://www.w3.org/2002/ws/databinding/examples/6/09/" elementFormDefault="qualified" finalDefault="#all">
  <xs:element name="finalDefault" type="xs:string" />
</xs:schema>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [FinalDefault01]:

  <ex:finalDefault>foo</ex:finalDefault>

2.1.6 BlockDefault

An [XML 1.0] document exhibits the BlockDefault pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/BlockDefault when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./@blockDefault

The following example [XML Schema 1.0] document [BlockDefault] illustrates the use of the BlockDefault pattern:

<xs:schema targetNamespace="http://www.w3.org/2002/ws/databinding/examples/6/09/" elementFormDefault="qualified" blockDefault="#all">
  <xs:element name="blockDefault" type="xs:string" />
</xs:schema>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [BlockDefault01]:

  <ex:blockDefault>foo</ex:blockDefault>

2.2 Annotations

2.2.1 DocumentationElement

An [XML 1.0] document exhibits the DocumentationElement pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/DocumentationElement when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:annotation/xs:documentation/ (.., ., .//*,
.//@*)

The following example [XML Schema 1.0] extract illustrates the use of the DocumentationElement pattern within an [XML Schema 1.0] document [DocumentationElement]:

<xs:annotation>
  <xs:documentationxml:lang="en" />
</xs:annotation>
<xs:element name="documentationElement" type="xs:string">
  <xs:annotation>
    <xs:documentationxml:lang="en" />
  </xs:annotation>
</xs:element>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [DocumentationElement01]:

  <ex:documentationElement>hello world</ex:documentationElement>

2.3 Properties

2.3.1 IdentifierName

An [XML 1.0] document exhibits the IdentifierName pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/IdentifierName when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//.[matches(@name, "^[A-Za-z_]([A-Za-z0-9_]{0,31})$")]/
(@name)

Note, this pattern represents a subset of the native identifier formats supported by many, but not all, implementations and is therefore most likely to be supported by a databinding tools which directly maps an [XML 1.0] NCName to an native identifier.

The NCName used to declare an [XML 1.0] attribute MUST NOT be used as the declared NCName of a child element. ^†

The following example [XML Schema 1.0] extract illustrates the use of the IdentifierName pattern within an [XML Schema 1.0] document [IdentifierName]:

<xs:element name="identifierName" type="xs:string" />

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [IdentifierName02]:

  <ex:identifierName>Hello</ex:identifierName>

2.3.2 NonIdentifierName

An [XML 1.0] document exhibits the NonIdentifierName pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/NonIdentifierName when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//.[@name
and not(matches(@name, "^[A-Za-z_]([A-Za-z0-9_]{0,31})$"))]/
(@name)

The following example [XML Schema 1.0] extract illustrates the use of the NonIdentifierName pattern within an [XML Schema 1.0] document [NonIdentifierName]:

<xs:element name="non-Identifier-Name" type="xs:string" />

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [NonIdentifierName02]:

  <ex:non-Identifier-Name>Hello</ex:non-Identifier-Name>

2.3.3 NotMixed

An [XML 1.0] document exhibits the NotMixed pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/NotMixed when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//.[@mixed =
'false']/ (@mixed)

2.3.4 MinOccurs1

An [XML 1.0] document exhibits the MinOccurs1 pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/MinOccurs1 when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//.[@minOccurs =
'1']/ (@minOccurs)

2.3.5 MaxOccurs1

An [XML 1.0] document exhibits the MaxOccurs1 pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/MaxOccurs1 when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//.[@maxOccurs =
'1']/ (@maxOccurs)

2.3.6 Id

An [XML 1.0] document exhibits the Id pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/Id when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//@id

The following example [XML Schema 1.0] extract illustrates the use of the Id pattern within an [XML Schema 1.0] document [IdExample]:

<xs:element name="idExample" type="ex:IdExample" id="node1" />
<xs:complexType name="IdExample" id="node2">
  <xs:sequence id="node3">
    <xs:element name="text" type="xs:string" minOccurs="0" id="node4" />
  </xs:sequence>
  <xs:attribute name="string" type="xs:string" id="node5" />
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [IdExample01]:

  <ex:idExample string="hello"/>

2.3.7 ComplexTypeConcrete

An [XML 1.0] document exhibits the ComplexTypeConcrete pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ComplexTypeConcrete when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:complexType[@abstract='false']/
(@abstract)

2.3.8 GlobalElementConcrete

An [XML 1.0] document exhibits the GlobalElementConcrete pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/GlobalElementConcrete when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:element[@abstract='false']/ (@abstract)

2.3.9 ElementFinal

An [XML 1.0] document exhibits the ElementFinal pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementFinal when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element/
(@final)

2.4 Import and Include

2.4.1 ImportTypesNamespace

An [XML 1.0] document exhibits the ImportTypesNamespace pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ImportTypesNamespace when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:import[@namespace and not(@schemaLocation) and
(@namespace = ../xs:schema/@targetNamespace)]/ (.,
@namespace)

This pattern is designed to capture a reference to a namespace defined within a WSDL document types section.

2.4.2 ImportNamespace

An [XML 1.0] document exhibits the ImportNamespace pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ImportNamespace when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:import[@namespace and not(@schemaLocation) and
not(@namespace = 'http://www.w3.org/2001/XMLSchema')]/ (.,
@namespace)

2.4.3 ImportSchema

An [XML 1.0] document exhibits the ImportSchema pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ImportSchema when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:import[@namespace and @schemaLocation]/ (., @namespace,
@schemaLocation)

2.4.4 Include

An [XML 1.0] document exhibits the Include pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/Include when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:include[@schemaLocation]/ (.,
@schemaLocation)

The following example [XML Schema 1.0] extract illustrates the use of the Include pattern within an [XML Schema 1.0] document [Include]:

<xs:includeschemaLocation="http://www.w3.org/2002/ws/databinding/examples/6/09/static/Included.xsd" />

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [Include01]:

  <ex:include>This is the include (with schemaLocation) example</ex:include>

2.5 Global Element Declarations

2.5.1 GlobalElement

An [XML 1.0] document exhibits the GlobalElement pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/GlobalElement when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:element[@name and @type and contains(@type, ':')]/ (.,
@name, @type)

2.5.2 GlobalElementBlock

An [XML 1.0] document exhibits the GlobalElementBlock pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/GlobalElementBlock when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:element/ (@block)

2.5.3 GlobalElementFinal

An [XML 1.0] document exhibits the GlobalElementFinal pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/GlobalElementFinal when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:element/ (@final)

2.5.4 GlobalElementSequence

An [XML 1.0] document exhibits the GlobalElementSequence pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/GlobalElementSequence when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:element[@name]/xs:complexType/xs:sequence[xs:element]/
(../../(., @name), .., ., xs:element/(., @name))

The following example [XML Schema 1.0] extract illustrates the use of the GlobalElementSequence pattern within an [XML Schema 1.0] document [GlobalElementSequence]:

<xs:elementname="globalElementSequence">
  <xs:complexType>
    <xs:sequence>
      <xs:elementname="foo" type="xs:string" />
      <xs:elementname="bar" type="xs:string" />
    </xs:sequence>
  </xs:complexType>
</xs:element>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [GlobalElementSequence01]:

  <ex:globalElementSequence>
      <ex:foo>one</ex:foo>
      <ex:bar>two</ex:bar>
   </ex:globalElementSequence>

2.6 Global Attribute Declarations

2.6.1 GlobalAttribute

An [XML 1.0] document exhibits the GlobalAttribute pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/GlobalAttribute when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

./xs:attribute[@name and @type and contains(@type, ":")]/ (.,
@name, @type)

2.7 Element Declarations

2.7.1 ElementMinOccurs0

An [XML 1.0] document exhibits the ElementMinOccurs0 pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementMinOccurs0 when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@minOccurs = '0' and (not(@maxOccurs) or
@maxOccurs = '1')]/ (@minOccurs, @maxOccurs)

The following example [XML Schema 1.0] extract illustrates the use of the ElementMinOccurs0 pattern within an [XML Schema 1.0] document [ElementMinOccurs0]:

<xs:element name="elementMinOccurs0" type="ex:ElementMinOccurs0" />
<xs:complexType name="ElementMinOccurs0">
  <xs:sequence>
    <xs:element name="firstName" type="xs:string" />
    <xs:element name="middleName" type="xs:string" minOccurs="0" />
    <xs:element name="lastName" type="xs:string" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementMinOccurs001]:

  <ex:elementMinOccurs0>
      <ex:firstName>Paul</ex:firstName>
      <ex:lastName>Downey</ex:lastName>
   </ex:elementMinOccurs0>

as is the following element when included in an instance document [ElementMinOccurs002]:

  <ex:elementMinOccurs0>
      <ex:firstName>Paul</ex:firstName>
      <ex:middleName>Sumner</ex:middleName>
      <ex:lastName>Downey</ex:lastName>
   </ex:elementMinOccurs0>

2.7.2 ElementMinOccurs1

An [XML 1.0] document exhibits the ElementMinOccurs1 pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementMinOccurs1 when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@minOccurs = '1' and (not(@maxOccurs) or
@maxOccurs = '1')]/ (@minOccurs, @maxOccurs)

The following example [XML Schema 1.0] extract illustrates the use of the ElementMinOccurs1 pattern within an [XML Schema 1.0] document [ElementMinOccurs1]:

<xs:element name="elementMinOccurs1" type="ex:ElementMinOccurs1" />
<xs:complexType name="ElementMinOccurs1">
  <xs:sequence>
    <xs:element name="elementMinOccurs1item" type="xs:string" minOccurs="1" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementMinOccurs101]:

  <ex:elementMinOccurs1>
      <ex:elementMinOccurs1item>item1</ex:elementMinOccurs1item>
   </ex:elementMinOccurs1>

2.7.3 ElementMaxOccurs1

An [XML 1.0] document exhibits the ElementMaxOccurs1 pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementMaxOccurs1 when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[(not(@minOccurs) or @minOccurs = '1') and
@maxOccurs = '1']/ (@minOccurs, @maxOccurs)

The following example [XML Schema 1.0] extract illustrates the use of the ElementMaxOccurs1 pattern within an [XML Schema 1.0] document [ElementMaxOccurs1]:

<xs:element name="elementMaxOccurs1" type="ex:ElementMaxOccurs1" />
<xs:complexType name="ElementMaxOccurs1">
  <xs:sequence>
    <xs:element name="value" type="xs:string" minOccurs="1" maxOccurs="1" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementMaxOccurs101]:

  <ex:elementMaxOccurs1>
      <ex:value>44</ex:value>
   </ex:elementMaxOccurs1>

as is the following element when included in an instance document [ElementMaxOccurs102]:

  <ex:elementMaxOccurs1>
      <ex:value>4</ex:value>
   </ex:elementMaxOccurs1>

2.7.4 ElementMinOccurs0MaxOccursUnbounded

An [XML 1.0] document exhibits the ElementMinOccurs0MaxOccursUnbounded pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementMinOccurs0MaxOccursUnbounded when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@minOccurs = '0' and @maxOccurs = 'unbounded']/
(@minOccurs, @maxOccurs)

The following example [XML Schema 1.0] extract illustrates the use of the ElementMinOccurs0MaxOccursUnbounded pattern within an [XML Schema 1.0] document [NestedSequenceElementList]:

<xs:element name="nestedSequenceElementList" type="ex:NestedSequenceElementList" />
<xs:complexType name="NestedItem">
  <xs:sequence>
    <xs:element name="item" minOccurs="0" maxOccurs="unbounded" type="xs:string" />
  </xs:sequence>
</xs:complexType>
<xs:complexType name="NestedSequenceElementList">
  <xs:sequence>
    <xs:element name="nestedItem" minOccurs="0" maxOccurs="unbounded" type="ex:NestedItem" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [NestedSequenceElementList01]:

  <ex:nestedSequenceElementList>
      <ex:nestedItem>
         <ex:item>item onexone</ex:item>
         <ex:item>item onextwo</ex:item>
         <ex:item>item onexthree</ex:item>
         <ex:item>item onexfour</ex:item>
      </ex:nestedItem>
      <ex:nestedItem>
         <ex:item>item twoxone</ex:item>
         <ex:item>item twoxtwo</ex:item>
         <ex:item>item twoxthree</ex:item>
         <ex:item>item twoxfour</ex:item>
      </ex:nestedItem>
   </ex:nestedSequenceElementList>

The following example [XML Schema 1.0] extract illustrates the use of the ElementMinOccurs0MaxOccursUnbounded pattern within an [XML Schema 1.0] document [ElementMinOccurs0MaxOccursUnbounded]:

<xs:element name="durationList" type="ex:DurationList" />
<xs:complexType name="DurationList">
  <xs:sequence>
    <xs:element name="durationValue" type="xs:short" minOccurs="0" maxOccurs="unbounded" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementMinOccurs0MaxOccursUnbounded101]:

  <ex:durationList/>

as is the following element when included in an instance document [ElementMinOccurs0MaxOccursUnbounded102]:

  <ex:durationList>
      <ex:durationValue>24</ex:durationValue>
      <ex:durationValue>34</ex:durationValue>
      <ex:durationValue>44</ex:durationValue>
   </ex:durationList>

2.7.5 ElementMinOccurs1MaxOccursUnbounded

An [XML 1.0] document exhibits the ElementMinOccurs1MaxOccursUnbounded pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementMinOccurs1MaxOccursUnbounded when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[(not(@minOccurs) or @minOccurs = '1') and
@maxOccurs = 'unbounded']/ (@minOccurs, @maxOccurs)

The following example [XML Schema 1.0] extract illustrates the use of the ElementMinOccurs1MaxOccursUnbounded pattern within an [XML Schema 1.0] document [ElementMaxOccursUnbounded]:

<xs:element name="publications" type="ex:Publications" />
<xs:complexType name="Publications">
  <xs:sequence>
    <xs:element name="day" type="xs:string" maxOccurs="unbounded" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementMaxOccursUnbounded01]:

  <ex:publications>
      <ex:day>2002-09-24</ex:day>
      <ex:day>2003-04-14</ex:day>
      <ex:day>2004-03-31</ex:day>
      <ex:day>2005-06-04</ex:day>
      <ex:day>2006-07-03</ex:day>
   </ex:publications>

as is the following element when included in an instance document [ElementMaxOccursUnbounded02]:

  <ex:publications>
      <ex:day>2006-01-26</ex:day>
   </ex:publications>

The following example [XML Schema 1.0] extract illustrates the use of the ElementMinOccurs1MaxOccursUnbounded pattern within an [XML Schema 1.0] document [ElementMinOccurs1MaxOccursUnbounded]:

<xs:element name="ageList" type="ex:AgeList" />
<xs:complexType name="AgeList">
  <xs:sequence>
    <xs:element name="ageValue" type="xs:short" minOccurs="1" maxOccurs="unbounded" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementMinOccurs1MaxOccursUnbounded101]:

  <ex:ageList>
      <ex:ageValue>44</ex:ageValue>
   </ex:ageList>

as is the following element when included in an instance document [ElementMinOccurs1MaxOccursUnbounded102]:

  <ex:ageList>
      <ex:ageValue>24</ex:ageValue>
      <ex:ageValue>34</ex:ageValue>
      <ex:ageValue>44</ex:ageValue>
   </ex:ageList>

2.7.6 ElementFormQualified

An [XML 1.0] document exhibits the ElementFormQualified pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementFormQualified when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@form='qualified']/ (@form)

2.7.7 SequenceSingleRepeatedElement

An [XML 1.0] document exhibits the SequenceSingleRepeatedElement pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/SequenceSingleRepeatedElement when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:sequence[count(xs:element) = 1]/xs:element[@maxOccurs =
'unbounded']/ (., @maxOccurs)

The following example [XML Schema 1.0] extract illustrates the use of the SequenceSingleRepeatedElement pattern within an [XML Schema 1.0] document [SequenceElementList]:

<xs:element name="sequenceElementList" type="ex:SequenceElementList" />
<xs:complexType name="SequenceElementList">
  <xs:sequence>
    <xs:element name="item" minOccurs="0" maxOccurs="unbounded" type="xs:string" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [SequenceElementList01]:

  <ex:sequenceElementList>
      <ex:item>item one</ex:item>
      <ex:item>item two</ex:item>
      <ex:item>item three</ex:item>
      <ex:item>item four</ex:item>
   </ex:sequenceElementList>

as is the following element when included in an instance document [SequenceElementList02]:

  <ex:sequenceElementList>
      <ex:item>item one</ex:item>
   </ex:sequenceElementList>

and the following element when included in an instance document [SequenceElementList03]:

  <ex:sequenceElementList/>

2.7.8 ElementEmptySequence

An [XML 1.0] document exhibits the ElementEmptySequence pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementEmptySequence when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@name]/xs:complexType/xs:sequence[not(node())]/
(., .., ../.., ../../@name)

The following example [XML Schema 1.0] extract illustrates the use of the ElementEmptySequence pattern within an [XML Schema 1.0] document [ElementEmptySequence]:

<xs:elementname="elementEmptySequence">
  <xs:complexType>
    <xs:sequence />
  </xs:complexType>
</xs:element>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementEmptySequence01]:

  <ex:elementEmptySequence/>

2.7.9 ElementEmptyComplexType

An [XML 1.0] document exhibits the ElementEmptyComplexType pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementEmptyComplexType when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@name]/xs:complexType[not(node())]/ (., ..,
../@name)

The following example [XML Schema 1.0] extract illustrates the use of the ElementEmptyComplexType pattern within an [XML Schema 1.0] document [ElementEmptyComplexType]:

<xs:elementname="elementEmptyComplexType">
  <xs:complexType />
</xs:element>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementEmptyComplexType01]:

  <ex:elementEmptyComplexType/>

2.7.10 NillableElement

An [XML 1.0] document exhibits the NillableElement pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/NillableElement when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@nillable = 'true' and not(@minOccurs = '0')]/
(@nillable)

The following example [XML Schema 1.0] extract illustrates the use of the NillableElement pattern within an [XML Schema 1.0] document [NillableElement]:

<xs:element name="nillableMiddleName" type="ex:NillableMiddleName" />
<xs:complexType name="NillableMiddleName">
  <xs:sequence>
    <xs:element name="firstName" type="xs:string" />
    <xs:element name="middleName" type="xs:string" nillable="true" />
    <xs:element name="lastName" type="xs:string" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [NillableElement01]:

  <ex:nillableMiddleName>
      <ex:firstName>Paul</ex:firstName>
      <ex:middleName xsi:nil="true"/>
      <ex:lastName>Downey</ex:lastName>
   </ex:nillableMiddleName>

as is the following element when included in an instance document [NillableElement02]:

  <ex:nillableMiddleName>
      <ex:firstName>Paul</ex:firstName>
      <ex:middleName>Sumner</ex:middleName>
      <ex:lastName>Downey</ex:lastName>
   </ex:nillableMiddleName>

2.7.11 NotNillableElement

An [XML 1.0] document exhibits the NotNillableElement pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/NotNillableElement when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@nillable = 'false']/ (@nillable)

2.7.12 ElementTypeReference

An [XML 1.0] document exhibits the ElementTypeReference pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementTypeReference when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@name and @type and
namespace-uri-from-QName(resolve-QName(@type,.)) !=
'http://www.w3.org/2001/XMLSchema' and contains(@type, ':')]/ (.,
@name, @type)

The following example [XML Schema 1.0] extract illustrates the use of the ElementTypeReference pattern within an [XML Schema 1.0] document [ElementTypeReference]:

<xs:elementname="elementTypeReference" type="ex:ElementTypeReference" />
<xs:complexType name="ElementTypeReferenced">
  <xs:sequence>
    <xs:element name="referenced" type="xs:string" />
  </xs:sequence>
</xs:complexType>
<xs:complexType name="ElementTypeReference">
  <xs:sequence>
    <xs:elementname="text" type="ex:ElementTypeReferenced" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementTypeReference01]:

  <ex:elementTypeReference>
      <ex:text>
         <ex:referenced>foo</ex:referenced>
      </ex:text>
   </ex:elementTypeReference>

2.7.13 ElementReference

An [XML 1.0] document exhibits the ElementReference pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/ElementReference when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[@ref and contains(@ref, ':')]/ (.,
@ref)

The following example [XML Schema 1.0] extract illustrates the use of the ElementReference pattern within an [XML Schema 1.0] document [ElementReference]:

<xs:element name="customerName" type="ex:CustomerName" />
<xs:element name="firstName" type="xs:string" />
<xs:element name="lastName" type="xs:string" />
<xs:complexType name="CustomerName">
  <xs:sequence>
    <xs:elementref="ex:firstName" />
    <xs:elementref="ex:lastName" />
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [ElementReference01]:

  <ex:customerName>
      <ex:firstName>Bobby</ex:firstName>
      <ex:lastName>Sox</ex:lastName>
   </ex:customerName>

2.7.14 LocalElementComplexType

An [XML 1.0] document exhibits the LocalElementComplexType pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/LocalElementComplexType when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:element[not(parent::xs:schema)]/xs:complexType

The following example [XML Schema 1.0] extract illustrates the use of the LocalElementComplexType pattern within an [XML Schema 1.0] document [LocalElementComplexType]:

<xs:element name="localElementComplexType" type="ex:LocalElementComplexType" />
<xs:complexType name="LocalElementComplexType">
  <xs:sequence>
    <xs:element name="name">
      <xs:complexType>
        <xs:sequence>
          <xs:element name="firstName" type="xs:string" />
          <xs:element name="lastName" type="xs:string" />
        </xs:sequence>
      </xs:complexType>
    </xs:element>
  </xs:sequence>
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [LocalElementComplexType01]:

  <ex:localElementComplexType>
      <ex:name>
         <ex:firstName>Paul</ex:firstName>
         <ex:lastName>Paul</ex:lastName>
      </ex:name>
   </ex:localElementComplexType>

2.8 Attribute Declarations

2.8.1 AttributeFormUnqualified

An [XML 1.0] document exhibits the AttributeFormUnqualified pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/AttributeFormUnqualified when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:attribute[@form='unqualified']/ (@form)

2.8.2 AttributeOptional

An [XML 1.0] document exhibits the AttributeOptional pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/AttributeOptional when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:attribute[@use = 'optional']/ (@use)

The following example [XML Schema 1.0] extract illustrates the use of the AttributeOptional pattern within an [XML Schema 1.0] document [AttributeOptional]:

<xs:element name="premium" type="ex:Premium" />
<xs:complexType name="Premium">
  <xs:sequence>
    <xs:element name="amount" type="xs:string" />
  </xs:sequence>
  <xs:attribute name="id" type="xs:string" />
  <xs:attribute name="currency" type="xs:string" use="optional" />
</xs:complexType>

The following example [XML 1.0] element is valid against the above example [XML Schema 1.0] when included inside an instance document [AttributeOptional01]:

  <ex:premium id="1711" currency="EUR">
      <ex:amount>1250</ex:amount>
   </ex:premium>

as is the following element when included in an instance document [AttributeOptional02]:

  <ex:premium id="1712">
      <ex:amount>1250</ex:amount>
   </ex:premium>

2.8.3 AttributeReference

An [XML 1.0] document exhibits the AttributeReference pattern identified using the URI [RFC 3986] http://www.w3.org/2002/ws/databinding/patterns/6/09/AttributeReference when the following [XPath 2.0] expression applied to a document or element node located by //xs:schema results in an [XPath 2.0] node-set containing at least one node:

.//xs:attribute[@ref and contains(@ref, ":")]/ (.,
@ref)

The following example [XML Schema 1.0] extract illustrates the use of the AttributeReference pattern within an [XML Schema 1.0] document [AttributeReference]:

<xs:element name="clientName" type="ex:ClientName" />
<xs:attribute name="phoneNumber" type="xs:string" />
<xs:complexType name="ClientName">
  <xs:sequence>
    <xs:element name="firstName" type="xs:string" />
    <xs:element name="lastName" type="xs:string" />
  </xs:sequence>
  <