Showing:

Annotations
Attributes
Diagrams
Facets
Instances
Properties
Source
Used by
Imported schema xlink.xsd
Namespace http://www.w3.org/1999/xlink
Annotations
This schema document provides attribute declarations and attribute group, complex type and simple type definitions which can be used in the construction of user schemas to define the structure of particular linking constructs, e.g. <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xl="http://www.w3.org/1999/xlink"> <xs:import namespace="http://www.w3.org/1999/xlink" location="http://www.w3.org/1999/xlink.xsd"> <xs:element name="mySimple"> <xs:complexType> ... <xs:attributeGroup ref="xl:simpleAttrs"/> ... </xs:complexType> </xs:element> ... </xs:schema>
Properties
attribute form default: unqualified
element form default: unqualified
Element xlink:title
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1519 index28.tmp#id1518 index28.tmp#id1517
Type xlink:titleEltType
Properties
content: complex
abstract: true
mixed: true
Used by
Model ANY element from ANY namespace
Attributes
QName Type Fixed Default Use Annotation
xlink:type xlink:typeType title required
xml:lang union of(xs:language, restriction of xs:string) optional

lang (as an attribute name)

denotes an attribute whose value is a language code for the natural language of the content of any element; its value is inherited. This name is reserved by virtue of its definition in the XML specification.

Notes

Attempting to install the relevant ISO 2- and 3-letter codes as the enumerated possible values is probably never going to be a realistic possibility.

See BCP 47 at http://www.rfc-editor.org/rfc/bcp/bcp47.txt and the IANA language subtag registry at http://www.iana.org/assignments/language-subtag-registry for further information.

The union allows for the 'un-declaration' of xml:lang with the empty string.

Source
<xs:element name="title" type="xlink:titleEltType" abstract="true"/>
Element xlink:resource
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1524 index28.tmp#id1523 index28.tmp#id1522
Type xlink:resourceType
Properties
content: complex
abstract: true
mixed: true
Used by
Element Group xlink:extendedModel
Model ANY element from ANY namespace
Attributes
QName Type Fixed Default Use Annotation
xlink:label xlink:labelType optional
xlink:role xlink:roleType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType resource required
Source
<xs:element name="resource" type="xlink:resourceType" abstract="true"/>
Element xlink:locator
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1528 index28.tmp#id1516 index28.tmp#id1527 index28.tmp#id1526
Type xlink:locatorType
Properties
content: complex
abstract: true
Used by
Element Group xlink:extendedModel
Model xlink:title*
Children xlink:title
Instance
<xlink:locator xlink:href="" xlink:label="" xlink:role="" xlink:title="" xlink:type="locator">
  <xlink:title xml:lang="" xlink:type="title">{0,unbounded}</xlink:title>
</xlink:locator>
Attributes
QName Type Fixed Default Use Annotation
xlink:href xlink:hrefType required
xlink:label xlink:labelType optional
xlink:role xlink:roleType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType locator required
Source
<xs:element name="locator" type="xlink:locatorType" abstract="true"/>
Element xlink:arc
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1532 index28.tmp#id1516 index28.tmp#id1531 index28.tmp#id1530
Type xlink:arcType
Properties
content: complex
abstract: true
Used by
Element Group xlink:extendedModel
Model xlink:title*
Children xlink:title
Instance
<xlink:arc xlink:actuate="" xlink:arcrole="" xlink:from="" xlink:show="" xlink:title="" xlink:to="" xlink:type="arc">
  <xlink:title xml:lang="" xlink:type="title">{0,unbounded}</xlink:title>
</xlink:arc>
Attributes
QName Type Fixed Default Use Annotation
xlink:actuate xlink:actuateType optional
xlink:arcrole xlink:arcroleType optional
xlink:from xlink:fromType optional
xlink:show xlink:showType optional
xlink:title xlink:titleAttrType optional
xlink:to xlink:toType optional
xlink:type xlink:typeType arc required
Source
<xs:element name="arc" type="xlink:arcType" abstract="true"/>
Simple Type xlink:typeType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type restriction of xs:token
Facets
enumeration simple
enumeration extended
enumeration title
enumeration resource
enumeration locator
enumeration arc
Used by
Attribute @xlink:type
Source
<xs:simpleType name="typeType">
  <xs:restriction base="xs:token">
    <xs:enumeration value="simple"/>
    <xs:enumeration value="extended"/>
    <xs:enumeration value="title"/>
    <xs:enumeration value="resource"/>
    <xs:enumeration value="locator"/>
    <xs:enumeration value="arc"/>
  </xs:restriction>
</xs:simpleType>
Simple Type xlink:hrefType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type xs:anyURI
Used by
Attribute @xlink:href
Source
<xs:simpleType name="hrefType">
  <xs:restriction base="xs:anyURI"/>
</xs:simpleType>
Simple Type xlink:roleType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type restriction of xs:anyURI
Facets
minLength 1
Used by
Attribute @xlink:role
Source
<xs:simpleType name="roleType">
  <xs:restriction base="xs:anyURI">
    <xs:minLength value="1"/>
  </xs:restriction>
</xs:simpleType>
Simple Type xlink:arcroleType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type restriction of xs:anyURI
Facets
minLength 1
Used by
Attribute @xlink:arcrole
Source
<xs:simpleType name="arcroleType">
  <xs:restriction base="xs:anyURI">
    <xs:minLength value="1"/>
  </xs:restriction>
</xs:simpleType>
Simple Type xlink:titleAttrType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type xs:string
Used by
Attribute @xlink:title
Source
<xs:simpleType name="titleAttrType">
  <xs:restriction base="xs:string"/>
</xs:simpleType>
Simple Type xlink:showType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type restriction of xs:token
Facets
enumeration new
enumeration replace
enumeration embed
enumeration other
enumeration none
Used by
Attribute @xlink:show
Source
<xs:simpleType name="showType">
  <xs:restriction base="xs:token">
    <xs:enumeration value="new"/>
    <xs:enumeration value="replace"/>
    <xs:enumeration value="embed"/>
    <xs:enumeration value="other"/>
    <xs:enumeration value="none"/>
  </xs:restriction>
</xs:simpleType>
Simple Type xlink:actuateType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type restriction of xs:token
Facets
enumeration onLoad
enumeration onRequest
enumeration other
enumeration none
Used by
Attribute @xlink:actuate
Source
<xs:simpleType name="actuateType">
  <xs:restriction base="xs:token">
    <xs:enumeration value="onLoad"/>
    <xs:enumeration value="onRequest"/>
    <xs:enumeration value="other"/>
    <xs:enumeration value="none"/>
  </xs:restriction>
</xs:simpleType>
Simple Type xlink:labelType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type xs:NCName
Used by
Attribute @xlink:label
Source
<xs:simpleType name="labelType">
  <xs:restriction base="xs:NCName"/>
</xs:simpleType>
Simple Type xlink:fromType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type xs:NCName
Used by
Attribute @xlink:from
Source
<xs:simpleType name="fromType">
  <xs:restriction base="xs:NCName"/>
</xs:simpleType>
Simple Type xlink:toType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Type xs:NCName
Used by
Attribute @xlink:to
Source
<xs:simpleType name="toType">
  <xs:restriction base="xs:NCName"/>
</xs:simpleType>
Complex Type xlink:simple
Namespace http://www.w3.org/1999/xlink
Annotations
Intended for use as the type of user-declared elements to make them simple links.
Diagram
Diagram index28.tmp#id137 index28.tmp#id1512
Properties
mixed: true
Model ANY element from ANY namespace
Attributes
QName Type Fixed Default Use Annotation
xlink:actuate xlink:actuateType optional
xlink:arcrole xlink:arcroleType optional
xlink:href xlink:hrefType optional
xlink:role xlink:roleType optional
xlink:show xlink:showType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType simple optional
Source
<xs:complexType mixed="true" name="simple">
  <xs:annotation>
    <xs:documentation>Intended for use as the type of user-declared elements to make them
    simple links.</xs:documentation>
  </xs:annotation>
  <xs:group ref="xlink:simpleModel"/>
  <xs:attributeGroup ref="xlink:simpleAttrs"/>
</xs:complexType>
Complex Type xlink:titleEltType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1519 index28.tmp#id1518
Properties
mixed: true
Used by
Element xlink:title
Model ANY element from ANY namespace
Attributes
QName Type Fixed Default Use Annotation
xlink:type xlink:typeType title required
xml:lang union of(xs:language, restriction of xs:string) optional

lang (as an attribute name)

denotes an attribute whose value is a language code for the natural language of the content of any element; its value is inherited. This name is reserved by virtue of its definition in the XML specification.

Notes

Attempting to install the relevant ISO 2- and 3-letter codes as the enumerated possible values is probably never going to be a realistic possibility.

See BCP 47 at http://www.rfc-editor.org/rfc/bcp/bcp47.txt and the IANA language subtag registry at http://www.iana.org/assignments/language-subtag-registry for further information.

The union allows for the 'un-declaration' of xml:lang with the empty string.

Source
<xs:complexType mixed="true" name="titleEltType">
  <xs:group ref="xlink:titleModel"/>
  <xs:attributeGroup ref="xlink:titleAttrs"/>
</xs:complexType>
Complex Type xlink:resourceType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1524 index28.tmp#id1523
Properties
mixed: true
Used by
Element xlink:resource
Model ANY element from ANY namespace
Attributes
QName Type Fixed Default Use Annotation
xlink:label xlink:labelType optional
xlink:role xlink:roleType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType resource required
Source
<xs:complexType mixed="true" name="resourceType">
  <xs:group ref="xlink:resourceModel"/>
  <xs:attributeGroup ref="xlink:resourceAttrs"/>
</xs:complexType>
Complex Type xlink:locatorType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1528 index28.tmp#id1516 index28.tmp#id1527
Used by
Element xlink:locator
Model xlink:title*
Children xlink:title
Attributes
QName Type Fixed Default Use Annotation
xlink:href xlink:hrefType required
xlink:label xlink:labelType optional
xlink:role xlink:roleType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType locator required
Source
<xs:complexType name="locatorType">
  <xs:group ref="xlink:locatorModel"/>
  <xs:attributeGroup ref="xlink:locatorAttrs"/>
</xs:complexType>
Complex Type xlink:arcType
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1532 index28.tmp#id1516 index28.tmp#id1531
Used by
Element xlink:arc
Model xlink:title*
Children xlink:title
Attributes
QName Type Fixed Default Use Annotation
xlink:actuate xlink:actuateType optional
xlink:arcrole xlink:arcroleType optional
xlink:from xlink:fromType optional
xlink:show xlink:showType optional
xlink:title xlink:titleAttrType optional
xlink:to xlink:toType optional
xlink:type xlink:typeType arc required
Source
<xs:complexType name="arcType">
  <xs:group ref="xlink:arcModel"/>
  <xs:attributeGroup ref="xlink:arcAttrs"/>
</xs:complexType>
Complex Type xlink:extended
Namespace http://www.w3.org/1999/xlink
Annotations
Intended for use as the type of user-declared elements to make them extended links. Note that the elements referenced in the content model are all abstract. The intention is that by simply declaring elements with these as their substitutionGroup, all the right things will happen.
Diagram
Diagram index28.tmp#id1514 index28.tmp#id1516 index28.tmp#id1521 index28.tmp#id1525 index28.tmp#id1529 index28.tmp#id1515
Model xlink:title | xlink:resource | xlink:locator | xlink:arc
Children xlink:arc, xlink:locator, xlink:resource, xlink:title
Attributes
QName Type Fixed Default Use Annotation
xlink:role xlink:roleType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType extended required
Source
<xs:complexType name="extended">
  <xs:annotation>
    <xs:documentation>Intended for use as the type of user-declared elements to make them
    extended links.
    Note that the elements referenced in the content model are all abstract.
    The intention is that by simply declaring elements with these as their
    substitutionGroup, all the right things will happen.</xs:documentation>
  </xs:annotation>
  <xs:group ref="xlink:extendedModel" minOccurs="0" maxOccurs="unbounded"/>
  <xs:attributeGroup ref="xlink:extendedAttrs"/>
</xs:complexType>
Attribute @xlink:type
Namespace http://www.w3.org/1999/xlink
Type xlink:typeType
Properties
content: simple
Facets
enumeration simple
enumeration extended
enumeration title
enumeration resource
enumeration locator
enumeration arc
Used by
Source
<xs:attribute name="type" type="xlink:typeType"/>
Attribute @xlink:href
Namespace http://www.w3.org/1999/xlink
Type xlink:hrefType
Properties
content: simple
Used by
Source
<xs:attribute name="href" type="xlink:hrefType"/>
Attribute @xlink:role
Namespace http://www.w3.org/1999/xlink
Type xlink:roleType
Properties
content: simple
Facets
minLength 1
Used by
Source
<xs:attribute name="role" type="xlink:roleType"/>
Attribute @xlink:arcrole
Namespace http://www.w3.org/1999/xlink
Type xlink:arcroleType
Properties
content: simple
Facets
minLength 1
Used by
Attribute Groups xlink:arcAttrs, xlink:simpleAttrs
Source
<xs:attribute name="arcrole" type="xlink:arcroleType"/>
Attribute @xlink:title
Namespace http://www.w3.org/1999/xlink
Type xlink:titleAttrType
Properties
content: simple
Used by
Source
<xs:attribute name="title" type="xlink:titleAttrType"/>
Attribute @xlink:show
Namespace http://www.w3.org/1999/xlink
Type xlink:showType
Properties
content: simple
Facets
enumeration new
enumeration replace
enumeration embed
enumeration other
enumeration none
Used by
Attribute Groups xlink:arcAttrs, xlink:simpleAttrs
Source
<xs:attribute name="show" type="xlink:showType"/>
Attribute @xlink:actuate
Namespace http://www.w3.org/1999/xlink
Type xlink:actuateType
Properties
content: simple
Facets
enumeration onLoad
enumeration onRequest
enumeration other
enumeration none
Used by
Attribute Groups xlink:arcAttrs, xlink:simpleAttrs
Source
<xs:attribute name="actuate" type="xlink:actuateType"/>
Attribute @xlink:label
Namespace http://www.w3.org/1999/xlink
Type xlink:labelType
Properties
content: simple
Used by
Source
<xs:attribute name="label" type="xlink:labelType"/>
Attribute @xlink:from
Namespace http://www.w3.org/1999/xlink
Type xlink:fromType
Properties
content: simple
Used by
Attribute Group xlink:arcAttrs
Source
<xs:attribute name="from" type="xlink:fromType"/>
Attribute @xlink:to
Namespace http://www.w3.org/1999/xlink
Type xlink:toType
Properties
content: simple
Used by
Attribute Group xlink:arcAttrs
Source
<xs:attribute name="to" type="xlink:toType"/>
Element Group xlink:simpleModel
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Used by
Complex Type xlink:simple
Model ANY element from ANY namespace
Source
<xs:group name="simpleModel">
  <xs:sequence>
    <xs:any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
  </xs:sequence>
</xs:group>
Element Group xlink:extendedModel
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1516 index28.tmp#id1521 index28.tmp#id1525 index28.tmp#id1529
Used by
Complex Type xlink:extended
Model xlink:title | xlink:resource | xlink:locator | xlink:arc
Children xlink:arc, xlink:locator, xlink:resource, xlink:title
Source
<xs:group name="extendedModel">
  <xs:choice>
    <xs:element ref="xlink:title"/>
    <xs:element ref="xlink:resource"/>
    <xs:element ref="xlink:locator"/>
    <xs:element ref="xlink:arc"/>
  </xs:choice>
</xs:group>
Element Group xlink:titleModel
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Used by
Complex Type xlink:titleEltType
Model ANY element from ANY namespace
Source
<xs:group name="titleModel">
  <xs:sequence>
    <xs:any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
  </xs:sequence>
</xs:group>
Element Group xlink:resourceModel
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram
Used by
Complex Type xlink:resourceType
Model ANY element from ANY namespace
Source
<xs:group name="resourceModel">
  <xs:sequence>
    <xs:any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
  </xs:sequence>
</xs:group>
Element Group xlink:locatorModel
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1516
Used by
Complex Type xlink:locatorType
Model xlink:title*
Children xlink:title
Source
<xs:group name="locatorModel">
  <xs:sequence>
    <xs:element ref="xlink:title" minOccurs="0" maxOccurs="unbounded"/>
  </xs:sequence>
</xs:group>
Element Group xlink:arcModel
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id1516
Used by
Complex Type xlink:arcType
Model xlink:title*
Children xlink:title
Source
<xs:group name="arcModel">
  <xs:sequence>
    <xs:element ref="xlink:title" minOccurs="0" maxOccurs="unbounded"/>
  </xs:sequence>
</xs:group>
Attribute Group xlink:simpleAttrs
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id138 index28.tmp#id140 index28.tmp#id142 index28.tmp#id144 index28.tmp#id146 index28.tmp#id148 index28.tmp#id150
Used by
Attribute Group gml:AssociationAttributeGroup
Complex Type xlink:simple
Attributes
QName Type Fixed Default Use Annotation
xlink:actuate xlink:actuateType optional
xlink:arcrole xlink:arcroleType optional
xlink:href xlink:hrefType optional
xlink:role xlink:roleType optional
xlink:show xlink:showType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType simple optional
Source
<xs:attributeGroup name="simpleAttrs">
  <xs:attribute ref="xlink:type" fixed="simple"/>
  <xs:attribute ref="xlink:href"/>
  <xs:attribute ref="xlink:role"/>
  <xs:attribute ref="xlink:arcrole"/>
  <xs:attribute ref="xlink:title"/>
  <xs:attribute ref="xlink:show"/>
  <xs:attribute ref="xlink:actuate"/>
</xs:attributeGroup>
Attribute Group xlink:extendedAttrs
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id138 index28.tmp#id142 index28.tmp#id146
Used by
Complex Type xlink:extended
Attributes
QName Type Fixed Default Use Annotation
xlink:role xlink:roleType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType extended required
Source
<xs:attributeGroup name="extendedAttrs">
  <xs:attribute ref="xlink:type" fixed="extended" use="required"/>
  <xs:attribute ref="xlink:role"/>
  <xs:attribute ref="xlink:title"/>
</xs:attributeGroup>
Attribute Group xlink:titleAttrs
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id138 index29.tmp#id1520
Used by
Complex Type xlink:titleEltType
Attributes
QName Type Fixed Default Use Annotation
xlink:type xlink:typeType title required
xml:lang union of(xs:language, restriction of xs:string) optional

lang (as an attribute name)

denotes an attribute whose value is a language code for the natural language of the content of any element; its value is inherited. This name is reserved by virtue of its definition in the XML specification.

Notes

Attempting to install the relevant ISO 2- and 3-letter codes as the enumerated possible values is probably never going to be a realistic possibility.

See BCP 47 at http://www.rfc-editor.org/rfc/bcp/bcp47.txt and the IANA language subtag registry at http://www.iana.org/assignments/language-subtag-registry for further information.

The union allows for the 'un-declaration' of xml:lang with the empty string.

Source
<xs:attributeGroup name="titleAttrs">
  <xs:attribute ref="xlink:type" fixed="title" use="required"/>
  <xs:attribute ref="xml:lang">
    <xs:annotation>
      <xs:documentation>xml:lang is not required, but provides much of the
     motivation for title elements in addition to attributes, and so
     is provided here for convenience.</xs:documentation>
    </xs:annotation>
  </xs:attribute>
</xs:attributeGroup>
Attribute Group xlink:resourceAttrs
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id138 index28.tmp#id142 index28.tmp#id146 index28.tmp#id1506
Used by
Complex Type xlink:resourceType
Attributes
QName Type Fixed Default Use Annotation
xlink:label xlink:labelType optional
xlink:role xlink:roleType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType resource required
Source
<xs:attributeGroup name="resourceAttrs">
  <xs:attribute ref="xlink:type" fixed="resource" use="required"/>
  <xs:attribute ref="xlink:role"/>
  <xs:attribute ref="xlink:title"/>
  <xs:attribute ref="xlink:label"/>
</xs:attributeGroup>
Attribute Group xlink:locatorAttrs
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id138 index28.tmp#id140 index28.tmp#id142 index28.tmp#id146 index28.tmp#id1506
Used by
Complex Type xlink:locatorType
Attributes
QName Type Fixed Default Use Annotation
xlink:href xlink:hrefType required
xlink:label xlink:labelType optional
xlink:role xlink:roleType optional
xlink:title xlink:titleAttrType optional
xlink:type xlink:typeType locator required
Source
<xs:attributeGroup name="locatorAttrs">
  <xs:attribute ref="xlink:type" fixed="locator" use="required"/>
  <xs:attribute ref="xlink:href" use="required"/>
  <xs:attribute ref="xlink:role"/>
  <xs:attribute ref="xlink:title"/>
  <xs:attribute ref="xlink:label">
    <xs:annotation>
      <xs:documentation>label is not required, but locators have no particular
     XLink function if they are not labeled.</xs:documentation>
    </xs:annotation>
  </xs:attribute>
</xs:attributeGroup>
Attribute Group xlink:arcAttrs
Namespace http://www.w3.org/1999/xlink
Diagram
Diagram index28.tmp#id138 index28.tmp#id144 index28.tmp#id146 index28.tmp#id148 index28.tmp#id150 index28.tmp#id1508 index28.tmp#id1510
Used by
Complex Type xlink:arcType
Attributes
QName Type Fixed Default Use Annotation
xlink:actuate xlink:actuateType optional
xlink:arcrole xlink:arcroleType optional
xlink:from xlink:fromType optional
xlink:show xlink:showType optional
xlink:title xlink:titleAttrType optional
xlink:to xlink:toType optional
xlink:type xlink:typeType arc required
Source
<xs:attributeGroup name="arcAttrs">
  <xs:attribute ref="xlink:type" fixed="arc" use="required"/>
  <xs:attribute ref="xlink:arcrole"/>
  <xs:attribute ref="xlink:title"/>
  <xs:attribute ref="xlink:show"/>
  <xs:attribute ref="xlink:actuate"/>
  <xs:attribute ref="xlink:from"/>
  <xs:attribute ref="xlink:to">
    <xs:annotation>
      <xs:documentation>from and to have default behavior when values are missing</xs:documentation>
    </xs:annotation>
  </xs:attribute>
</xs:attributeGroup>