Table of Contents
Target Namespace
None
Version
0.5
Language
en
Element and Attribute Namespaces
Global element and attribute declarations belong to this schema's target namespace.
By default, local element declarations belong to this schema's target namespace.
By default, local attribute declarations have no namespace.
Schema Composition
This schema includes components from the following schema document(s):
Documentation
XML Schema for web-based events. (webEvent)
Version 0.7.1 (2007-05-21)
Created by Aperio Networks, LLC
contact@aperionetworks.com
Declared Namespaces
Prefix
Namespace
xml
http://www.w3.org/XML/1998/namespace
xs
http://www.w3.org/2001/XMLSchema
Schema Component Representation
<
xs:schema
xml:lang ="
en "
elementFormDefault ="
qualified "
version ="
0.5 ">
<xs:include
schemaLocation ="eventTypes.xsd "/>
<xs:include
schemaLocation ="presenterRoles.xsd "/>
<xs:include
schemaLocation ="eventHostRoles.xsd "/>
<xs:include
schemaLocation ="eventContactRoles.xsd "/>
<xs:include
schemaLocation ="admissionTypes.xsd "/>
<xs:include
schemaLocation ="categories.xsd "/>
...
</
xs:schema >
Name
admission
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
A string value denoting the price or requirement for admission for this web event
XML Instance Representation
<admission>
xs :string </admission>
Schema Component Representation
<
xs:element
name ="
admission "
type ="
xs :string
"/>
Name
admissionType
Used by (from the same schema document)
Element
webEvent
Type
admissionTypes
Nillable
no
Abstract
no
Documentation
Admission type for this web event. See enumerated values in admissionTypes.xsd
Name
background
Used by (from the same schema document)
Element
eventHost
Type
xs :string
Nillable
no
Abstract
no
Documentation
Company or organization background and/or description of products/services
XML Instance Representation
<background>
xs :string </background>
Schema Component Representation
<
xs:element
name ="
background "
type ="
xs :string
"/>
XML Instance Representation
<biography>
xs :string </biography>
Schema Component Representation
<
xs:element
name ="
biography "
type ="
xs :string
"/>
Name
categories
Used by (from the same schema document)
Element
webEvent
Type
categories
Nillable
no
Abstract
no
Documentation
Categories for this web event. See enumerated values in categories.xsd
Schema Component Representation
<
xs:element
name ="
categories "
type ="
categories
"/>
Name
description
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
Full description of this web event.
XML Instance Representation
<description>
xs :string </description>
Schema Component Representation
<
xs:element
name ="
description "
type ="
xs :string
"/>
Name
dialInConferenceNumber
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
The dial-in audio conference number for this web event, if applicable
XML Instance Representation
<dialInConferenceNumber>
xs :string </dialInConferenceNumber>
Schema Component Representation
<
xs:element
name ="
dialInConferenceNumber "
type ="
xs :string
"/>
Name
dialInConferencePasscode
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
The dial-in audio conference number pass or pin code for this web event, if applicable
XML Instance Representation
<dialInConferencePasscode>
xs :string </dialInConferencePasscode>
Schema Component Representation
<
xs:element
name ="
dialInConferencePasscode "
type ="
xs :string
"/>
Name
disclaimer
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
A disclaimer or legal notice for this web event
XML Instance Representation
<disclaimer>
xs :string </disclaimer>
Schema Component Representation
<
xs:element
name ="
disclaimer "
type ="
xs :string
"/>
XML Instance Representation
<email>
xs :string </email>
Schema Component Representation
<
xs:element
name ="
email "
type ="
xs :string
"/>
Name
endTime
Used by (from the same schema document)
Element
webEvent
Type
xs :dateTime
Nillable
no
Abstract
no
Documentation
The end date and time for this web event. Must be after the start time. (Use ISO 8601 per W3C.org)
XML Instance Representation
<endTime>
xs :dateTime </endTime>
Schema Component Representation
<
xs:element
name ="
endTime "
type ="
xs :dateTime
"/>
XML Instance Representation
<eventContact>
<!-- Mixed content -->
</eventContact>
Schema Component Representation
<
xs:element
name ="
eventContact ">
<
xs:complexType
mixed ="
true ">
<
xs:sequence >
<
xs:element
ref ="
firstName
"
minOccurs ="
0 "/>
<
xs:element
ref ="
lastName
"
minOccurs ="
0 "/>
<
xs:element
ref ="
jobTitle
"
minOccurs ="
0 "/>
<
xs:element
ref ="
website
"
minOccurs ="
0 "/>
<
xs:element
ref ="
email
"
minOccurs ="
0 "/>
<
xs:element
ref ="
phone
"
minOccurs ="
0 "/>
</
xs:sequence >
</
xs:complexType >
</
xs:element >
Name
eventContactRole
Used by (from the same schema document)
Element
eventContact
Type
eventContactRoles
Nillable
no
Abstract
no
Documentation
An event contact role as it relates to this web event. See enumerated values in eventContactRoles.xsd
Name
eventContacts
Used by (from the same schema document)
Element
webEvent
Type
Locally-defined complex type
Nillable
no
Abstract
no
Documentation
Contacts for this web event
XML Instance Representation
<eventContacts>
Start Sequence
[0..*]
End Sequence
</eventContacts>
Schema Component Representation
<
xs:element
name ="
eventContacts ">
<
xs:complexType >
<
xs:sequence
minOccurs ="
0 "
maxOccurs ="
unbounded ">
</
xs:sequence >
</
xs:complexType >
</
xs:element >
Name
eventHost
Used by (from the same schema document)
Element
eventHosts
Type
Locally-defined complex type
Nillable
no
Abstract
no
XML Instance Representation
<eventHost>
<!-- Mixed content -->
</eventHost>
Schema Component Representation
<
xs:element
name ="
eventHost ">
<
xs:complexType
mixed ="
true ">
<
xs:sequence >
<
xs:element
ref ="
website
"
minOccurs ="
0 "/>
<
xs:element
ref ="
phone
"
minOccurs ="
0 "/>
<
xs:element
ref ="
email
"
minOccurs ="
0 "/>
<
xs:element
ref ="
logoUrl
"
minOccurs ="
0 "/>
</
xs:sequence >
</
xs:complexType >
</
xs:element >
Name
eventHostRole
Used by (from the same schema document)
Element
eventHost
Type
eventHostRoles
Nillable
no
Abstract
no
Documentation
An event host role as it relates to this web event. See enumerated values in eventHostRoles.xsd
Name
eventHosts
Used by (from the same schema document)
Element
webEvent
Type
Locally-defined complex type
Nillable
no
Abstract
no
Documentation
Host, sponsor or partner organizations for this web event
XML Instance Representation
<eventHosts>
</eventHosts>
Schema Component Representation
<
xs:element
name ="
eventHosts ">
<
xs:complexType >
<
xs:sequence >
</
xs:sequence >
</
xs:complexType >
</
xs:element >
Name
eventLink
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
URL link to the web event or registration area for the web event
XML Instance Representation
<eventLink>
xs :string </eventLink>
Schema Component Representation
<
xs:element
name ="
eventLink "
type ="
xs :string
"/>
Name
eventType
Used by (from the same schema document)
Element
webEvent
Type
eventTypes
Nillable
no
Abstract
no
Documentation
Type of web event. See enumerated values in eventTypes.xsd
Schema Component Representation
<
xs:element
name ="
eventType "
type ="
eventTypes
"/>
Name
externalIdentification
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
An external identifier, often issued by the web event service provider
XML Instance Representation
<externalIdentification>
xs :string </externalIdentification>
Schema Component Representation
<
xs:element
name ="
externalIdentification "
type ="
xs :string
"/>
XML Instance Representation
<firstName>
xs :string </firstName>
Schema Component Representation
<
xs:element
name ="
firstName "
type ="
xs :string
"/>
Name
headshotUrl
Used by (from the same schema document)
Element
presenter
Type
xs :string
Nillable
no
Abstract
no
Documentation
Link to a headshot image of a presenter
XML Instance Representation
<headshotUrl>
xs :string </headshotUrl>
Schema Component Representation
<
xs:element
name ="
headshotUrl "
type ="
xs :string
"/>
Name
intendedAudience
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
Description of the intended audience for this web event
XML Instance Representation
<intendedAudience>
xs :string </intendedAudience>
Schema Component Representation
<
xs:element
name ="
intendedAudience "
type ="
xs :string
"/>
XML Instance Representation
<jobTitle>
xs :string </jobTitle>
Schema Component Representation
<
xs:element
name ="
jobTitle "
type ="
xs :string
"/>
Name
language
Used by (from the same schema document)
Element
webEvent
Type
xs :language
Nillable
no
Abstract
no
Documentation
Language for this web event, per W3C.org
XML Instance Representation
<language>
xs :language </language>
Schema Component Representation
<
xs:element
name ="
language "
type ="
xs :language
"/>
XML Instance Representation
<lastName>
xs :string </lastName>
Schema Component Representation
<
xs:element
name ="
lastName "
type ="
xs :string
"/>
XML Instance Representation
<linkDescription>
xs :string </linkDescription>
Schema Component Representation
<
xs:element
name ="
linkDescription "
type ="
xs :string
"/>
Name
logoUrl
Used by (from the same schema document)
Element
eventHost
Type
xs :string
Nillable
no
Abstract
no
Documentation
Link to a logo image for a company/organization
XML Instance Representation
<logoUrl>
xs :string </logoUrl>
Schema Component Representation
<
xs:element
name ="
logoUrl "
type ="
xs :string
"/>
Name
middleName
Used by (from the same schema document)
Element
presenter
Type
xs :string
Nillable
no
Abstract
no
Documentation
Middle name or initial
XML Instance Representation
<middleName>
xs :string </middleName>
Schema Component Representation
<
xs:element
name ="
middleName "
type ="
xs :string
"/>
Name
nameSuffix
Used by (from the same schema document)
Element
presenter
Type
xs :string
Nillable
no
Abstract
no
Documentation
Suffix for a person's name (e.g., 'Ph.D' or Esq.')
XML Instance Representation
<nameSuffix>
xs :string </nameSuffix>
Schema Component Representation
<
xs:element
name ="
nameSuffix "
type ="
xs :string
"/>
Name
onDemand
Used by (from the same schema document)
Element
webEvent
Type
xs :boolean
Nillable
no
Abstract
no
Documentation
If this web event is available on-demand (in a recorded mode)
XML Instance Representation
<onDemand>
xs :boolean </onDemand>
Schema Component Representation
<
xs:element
name ="
onDemand "
type ="
xs :boolean
"/>
Name
onDemandEventLink
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
If this web event is available on-demand, the URL link to view this recorded web event (if different from 'eventLink' element)
XML Instance Representation
<onDemandEventLink>
xs :string </onDemandEventLink>
Schema Component Representation
<
xs:element
name ="
onDemandEventLink "
type ="
xs :string
"/>
Name
onDemandUntil
Used by (from the same schema document)
Element
webEvent
Type
xs :date
Nillable
no
Abstract
no
Documentation
If this web event is available on-demand, the date it is available on-demand until. (Use YYYY-MM-DD per W3C.org)
XML Instance Representation
<onDemandUntil>
xs :date </onDemandUntil>
Schema Component Representation
<
xs:element
name ="
onDemandUntil "
type ="
xs :date
"/>
XML Instance Representation
<organization>
xs :string </organization>
Schema Component Representation
<
xs:element
name ="
organization "
type ="
xs :string
"/>
XML Instance Representation
<phone>
xs :string </phone>
Schema Component Representation
<
xs:element
name ="
phone "
type ="
xs :string
"/>
Name
preferredTimeZone
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
Preferred time zone for publishing this web event listing. (Use standard tz (Olsen) values - http://www.twinsun.com/tz/tz-link.htm)
XML Instance Representation
<preferredTimeZone>
xs :string </preferredTimeZone>
Schema Component Representation
<
xs:element
name ="
preferredTimeZone "
type ="
xs :string
"/>
Name
presenter
Used by (from the same schema document)
Element
presenters
Type
Locally-defined complex type
Nillable
no
Abstract
no
XML Instance Representation
<presenter>
<!-- Mixed content -->
</presenter>
Schema Component Representation
<
xs:element
name ="
presenter ">
<
xs:complexType
mixed ="
true ">
<
xs:sequence >
<
xs:element
ref ="
jobTitle
"
minOccurs ="
0 "/>
<
xs:element
ref ="
biography
"
minOccurs ="
0 "/>
<
xs:element
ref ="
website
"
minOccurs ="
0 "/>
<
xs:element
ref ="
email
"
minOccurs ="
0 "/>
<
xs:element
ref ="
phone
"
minOccurs ="
0 "/>
</
xs:sequence >
</
xs:complexType >
</
xs:element >
Name
presenterRole
Used by (from the same schema document)
Element
presenter
Type
presenterRoles
Nillable
no
Abstract
no
Documentation
A presenter role as it relates to this web event. See enumerated values in presenterRoles.xsd
Name
presenters
Used by (from the same schema document)
Element
webEvent
Type
Locally-defined complex type
Nillable
no
Abstract
no
Documentation
Presenters for this web event
XML Instance Representation
<presenters>
Start Choice
[0..*]
End Choice
</presenters>
Schema Component Representation
<
xs:element
name ="
presenters ">
<
xs:complexType >
<
xs:choice
minOccurs ="
0 "
maxOccurs ="
unbounded ">
</
xs:choice >
</
xs:complexType >
</
xs:element >
XML Instance Representation
<relatedLink>
<!-- Mixed content -->
</relatedLink>
Schema Component Representation
<
xs:element
name ="
relatedLink ">
<
xs:complexType
mixed ="
true ">
<
xs:sequence >
<
xs:element
ref ="
title
"/>
<
xs:element
ref ="
url
"/>
</
xs:sequence >
</
xs:complexType >
</
xs:element >
Name
relatedLinks
Used by (from the same schema document)
Element
webEvent
Type
Locally-defined complex type
Nillable
no
Abstract
no
Documentation
Related links (e.g., supporting white papers, case studies, websites) for this web event
XML Instance Representation
<relatedLinks>
</relatedLinks>
Schema Component Representation
<
xs:element
name ="
relatedLinks ">
<
xs:complexType >
<
xs:sequence >
</
xs:sequence >
</
xs:complexType >
</
xs:element >
Name
source
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
Media announcement source for this web event listing
XML Instance Representation
<source>
xs :string </source>
Schema Component Representation
<
xs:element
name ="
source "
type ="
xs :string
"/>
Name
startTime
Used by (from the same schema document)
Element
webEvent
Type
xs :dateTime
Nillable
no
Abstract
no
Documentation
The start date and time for this web event. (Use ISO 8601 per W3C.org)
XML Instance Representation
<startTime>
xs :dateTime </startTime>
Schema Component Representation
<
xs:element
name ="
startTime "
type ="
xs :dateTime
"/>
Name
subTitle
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
Subtitle of the web event
XML Instance Representation
<subTitle>
xs :string </subTitle>
Schema Component Representation
<
xs:element
name ="
subTitle "
type ="
xs :string
"/>
Name
summary
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
Brief summary for this web event.
XML Instance Representation
<summary>
xs :string </summary>
Schema Component Representation
<
xs:element
name ="
summary "
type ="
xs :string
"/>
Element: tags
Name
tags
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
Tags related to the subject matter for this web event
Schema Component Representation
<
xs:element
name ="
tags "
type ="
xs :string
"/>
Name
technicalRequirements
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
A description of the technical requirements to attend this web event
XML Instance Representation
<technicalRequirements>
xs :string </technicalRequirements>
Schema Component Representation
<
xs:element
name ="
technicalRequirements "
type ="
xs :string
"/>
XML Instance Representation
<title>
xs :string </title>
Schema Component Representation
<
xs:element
name ="
title "
type ="
xs :string
"/>
Element: url
Schema Component Representation
<
xs:element
name ="
url "
type ="
xs :string
"/>
Name
webEvent
Used by (from the same schema document)
Element
webEvents
Type
Locally-defined complex type
Nillable
no
Abstract
no
Documentation
A web-based event.
XML Instance Representation
<webEvent>
<!-- Mixed content -->
</webEvent>
Schema Component Representation
<
xs:element
name ="
webEvent ">
<
xs:complexType
mixed ="
true ">
<
xs:sequence >
<
xs:element
ref ="
language
"
minOccurs ="
0 "/>
<
xs:element
ref ="
source
"
minOccurs ="
0 "/>
<
xs:element
ref ="
title
"/>
<
xs:element
ref ="
subTitle
"
minOccurs ="
0 "/>
<
xs:element
ref ="
eventType
"
minOccurs ="
0 "
maxOccurs ="
1 "/>
<
xs:element
ref ="
categories
"
minOccurs ="
0 "
maxOccurs ="
3 "/>
<
xs:element
ref ="
tags
"
minOccurs ="
0 "
maxOccurs ="
10 "/>
<
xs:element
ref ="
admission
"
minOccurs ="
0 "/>
<
xs:element
ref ="
presenters
"
minOccurs ="
0 "
maxOccurs ="
unbounded "/>
<
xs:element
ref ="
eventContacts
"
minOccurs ="
0 "
maxOccurs ="
unbounded "/>
<
xs:element
ref ="
eventHosts
"
minOccurs ="
0 "
maxOccurs ="
unbounded "/>
<
xs:element
ref ="
relatedLinks
"
minOccurs ="
0 "
maxOccurs ="
unbounded "/>
</
xs:sequence >
</
xs:complexType >
</
xs:element >
Schema Component Representation
<
xs:element
name ="
webEvents ">
<
xs:complexType >
<
xs:sequence >
</
xs:sequence >
</
xs:complexType >
</
xs:element >
XML Instance Representation
<website>
xs :string </website>
Schema Component Representation
<
xs:element
name ="
website "
type ="
xs :string
"/>
Name
whatYouWillLearn
Used by (from the same schema document)
Element
webEvent
Type
xs :string
Nillable
no
Abstract
no
Documentation
A description of what the intended audience will learn by attending this web event
XML Instance Representation
<whatYouWillLearn>
xs :string </whatYouWillLearn>
Schema Component Representation
<
xs:element
name ="
whatYouWillLearn "
type ="
xs :string
"/>
Complex Type:
Schema Component Type
AusAddress
Schema Component Name
Super-types:
Address < AusAddress (by extension)
Sub-types:
QLDAddress (by restriction)
If this schema component is a type definition, its type hierarchy is shown in a gray-bordered box.
The table above displays the properties of this schema component.
XML Instance Representation
<...
country="Australia "
>
<unitNo> string </unitNo> [0..1]
<houseNo> string </houseNo> [1]
<street> string </street> [1]
Start Choice
[1]
<city> string </city> [1]
<town> string </town> [1]
End Choice
<state> AusStates </state> [1]
<postcode> string <<pattern = [1-9][0-9]{3}>> </postcode> [1]
?
</...>
The XML Instance Representation table above shows the schema component's content as an XML instance.
The minimum and maximum occurrence of elements and attributes are provided in square brackets, e.g. [0..1].
Model group information are shown in gray, e.g. Start Choice ... End Choice.
For type derivations, the elements and attributes that have been added to or changed from the base type's content are shown in bold .
If an element/attribute has a fixed value, the fixed value is shown in green, e.g. country="Australia".
Otherwise, the type of the element/attribute is displayed.
If the element/attribute's type is in the schema, a link is provided to it.
For local simple type definitions, the constraints are displayed in angle brackets, e.g. <<pattern = [1-9][0-9]{3}>>.
If a local element/attribute has documentation, it will be displayed in a window that pops up when the question mark inside the attribute or next to the element is clicked, e.g. <postcode>.
Schema Component Representation
<complexType
name ="AusAddress ">
<complexContent >
<extension
base ="
Address
">
<sequence >
<element
name ="state " type ="
AusStates
"/>
<element
name ="postcode ">
<simpleType >
<restriction
base ="
string
">
<pattern
value ="[1-9][0-9]{3} "/>
</restriction >
</simpleType >
</element >
</sequence >
<attribute
name ="country " type ="
string
" fixed ="Australia "/>
</extension >
</complexContent >
</complexType >
The Schema Component Representation table above displays the underlying XML representation of the schema component. (Annotations are not shown.)
Abstract
(Applies to complex type definitions and element declarations). An abstract element or complex type cannot used to validate an element instance. If there is a reference to an abstract element, only element declarations that can substitute the abstract element can be used to validate the instance. For references to abstract type definitions, only derived types can be used.
All Model Group
Child elements can be provided in any order in instances. See: http://www.w3.org/TR/xmlschema-1/#element-all .
Choice Model Group
Only one from the list of child elements and model groups can be provided in instances. See: http://www.w3.org/TR/xmlschema-1/#element-choice .
Collapse Whitespace Policy
Replace tab, line feed, and carriage return characters with space character (Unicode character 32). Then, collapse contiguous sequences of space characters into single space character, and remove leading and trailing space characters.
Disallowed Substitutions
(Applies to element declarations). If substitution is specified, then substitution group members cannot be used in place of the given element declaration to validate element instances. If derivation methods , e.g. extension, restriction, are specified, then the given element declaration will not validate element instances that have types derived from the element declaration's type using the specified derivation methods. Normally, element instances can override their declaration's type by specifying an xsi:type attribute.
Key Constraint
Like Uniqueness Constraint , but additionally requires that the specified value(s) must be provided. See: http://www.w3.org/TR/xmlschema-1/#cIdentity-constraint_Definitions .
Key Reference Constraint
Ensures that the specified value(s) must match value(s) from a Key Constraint or Uniqueness Constraint . See: http://www.w3.org/TR/xmlschema-1/#cIdentity-constraint_Definitions .
Model Group
Groups together element content, specifying the order in which the element content can occur and the number of times the group of element content may be repeated. See: http://www.w3.org/TR/xmlschema-1/#Model_Groups .
Nillable
(Applies to element declarations). If an element declaration is nillable, instances can use the xsi:nil attribute. The xsi:nil attribute is the boolean attribute, nil , from the http://www.w3.org/2001/XMLSchema-instance namespace. If an element instance has an xsi:nil attribute set to true, it can be left empty, even though its element declaration may have required content.
Notation
A notation is used to identify the format of a piece of data. Values of elements and attributes that are of type, NOTATION, must come from the names of declared notations. See: http://www.w3.org/TR/xmlschema-1/#cNotation_Declarations .
Preserve Whitespace Policy
Preserve whitespaces exactly as they appear in instances.
Prohibited Derivations
(Applies to type definitions). Derivation methods that cannot be used to create sub-types from a given type definition.
Prohibited Substitutions
(Applies to complex type definitions). Prevents sub-types that have been derived using the specified derivation methods from validating element instances in place of the given type definition.
Replace Whitespace Policy
Replace tab, line feed, and carriage return characters with space character (Unicode character 32).
Sequence Model Group
Child elements and model groups must be provided in the specified order in instances. See: http://www.w3.org/TR/xmlschema-1/#element-sequence .
Substitution Group
Elements that are members of a substitution group can be used wherever the head element of the substitution group is referenced.
Substitution Group Exclusions
(Applies to element declarations). Prohibits element declarations from nominating themselves as being able to substitute a given element declaration, if they have types that are derived from the original element's type using the specified derivation methods.
Target Namespace
The target namespace identifies the namespace that components in this schema belongs to. If no target namespace is provided, then the schema components do not belong to any namespace.
Uniqueness Constraint
Ensures uniqueness of an element/attribute value, or a combination of values, within a specified scope. See: http://www.w3.org/TR/xmlschema-1/#cIdentity-constraint_Definitions .