5.1 http://schemas.microsoft.com/office/webextensions/webextension/2010/11 Schema

 <xsd:schema targetNamespace="http://schemas.microsoft.com/office/webextensions/webextension/2010/11" elementFormDefault="qualified" attributeFormDefault="unqualified" xmlns="http://schemas.microsoft.com/office/webextensions/webextension/2010/11" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main" xmlns:a14="http://schemas.microsoft.com/office/drawing/2010/main" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:o="urn:schemas-microsoft-com:office:office">
   <xsd:import namespace="http://schemas.openxmlformats.org/drawingml/2006/main" schemaLocation="oartbasetypes.xsd"/>
   <xsd:import namespace="http://schemas.openxmlformats.org/drawingml/2006/main" schemaLocation="oartspeffects.xsd"/>
   <xsd:import namespace="http://schemas.openxmlformats.org/officeDocument/2006/relationships" schemaLocation="orel.xsd"/>
   <xsd:complexType name="CT_WebExtensionPartRef">
     <xsd:attribute ref="r:id" use="required"/>
   </xsd:complexType>
   <xsd:complexType name="CT_OsfWebExtensionProperty">
     <xsd:attribute name="name" type="xsd:string" use="required"/>
     <xsd:attribute name="value" type="xsd:string" use="required"/>
   </xsd:complexType>
   <xsd:complexType name="CT_OsfWebExtensionPropertyBag">
     <xsd:sequence>
       <xsd:element name="property" minOccurs="0" maxOccurs="unbounded" type="CT_OsfWebExtensionProperty"/>
     </xsd:sequence>
   </xsd:complexType>
   <xsd:complexType name="CT_OsfWebExtensionBinding">
     <xsd:sequence>
       <xsd:element name="extLst" type="a:CT_OfficeArtExtensionList" minOccurs="0" maxOccurs="1"/>
     </xsd:sequence>
     <xsd:attribute name="id" type="xsd:string" use="required"/>
     <xsd:attribute name="type" type="xsd:string" use="required"/>
     <xsd:attribute name="appref" type="xsd:string" use="required"/>
   </xsd:complexType>
   <xsd:complexType name="CT_OsfWebExtensionBindingList">
     <xsd:sequence>
       <xsd:element name="binding" minOccurs="0" maxOccurs="unbounded" type="CT_OsfWebExtensionBinding"/>
     </xsd:sequence>
   </xsd:complexType>
   <xsd:complexType name="CT_OsfWebExtensionReference">
     <xsd:sequence>
       <xsd:element name="extLst" type="a:CT_OfficeArtExtensionList" minOccurs="0" maxOccurs="1"/>
     </xsd:sequence>
     <xsd:attribute name="id" type="xsd:string" use="required"/>
     <xsd:attribute name="version" type="xsd:string" use="required"/>
     <xsd:attribute name="store" type="xsd:string"/>
     <xsd:attribute name="storeType" type="xsd:string" use="optional"/>
   </xsd:complexType>
   <xsd:complexType name="CT_OsfWebExtensionReferenceList">
     <xsd:sequence>
       <xsd:element name="reference" minOccurs="0" maxOccurs="unbounded" type="CT_OsfWebExtensionReference"/>
     </xsd:sequence>
   </xsd:complexType>
   <xsd:complexType name="CT_ContainsCustomFunctions">
     <xsd:attribute name="val" type="xsd:boolean" use="optional" default="false"/>
   </xsd:complexType>
   <xsd:complexType name="CT_CustomFunctionList">
     <xsd:sequence>
       <xsd:element name="customFunctionIds" type="xsd:string" minOccurs="0" maxOccurs="unbounded"/>
     </xsd:sequence>
   </xsd:complexType>
   <xsd:complexType name="CT_BackgroundAppData">
     <xsd:attribute name="state" type="xsd:int" use="required"/>
     <xsd:attribute name="runtimeId" type="xsd:string" use="required"/>
   </xsd:complexType>
   <xsd:complexType name="CT_OsfWebExtension">
     <xsd:sequence>
       <xsd:element name="reference" type="CT_OsfWebExtensionReference"/>
       <xsd:element name="alternateReferences" type="CT_OsfWebExtensionReferenceList" minOccurs="0" maxOccurs="1"/>
       <xsd:element name="properties" type="CT_OsfWebExtensionPropertyBag"/>
       <xsd:element name="bindings" type="CT_OsfWebExtensionBindingList"/>
       <xsd:element name="snapshot" type="a:CT_Blip" minOccurs="0" maxOccurs="1"/>
       <xsd:element name="extLst" type="a:CT_OfficeArtExtensionList" minOccurs="0" maxOccurs="1"/>
     </xsd:sequence>
     <xsd:attribute name="id" type="xsd:string" use="required"/>
     <xsd:attribute name="frozen" type="xsd:boolean" use="optional" default="false"/>
   </xsd:complexType>
   <xsd:element name="webextension" type="CT_OsfWebExtension"/>
   <xsd:element name="webextensionref" type="CT_WebExtensionPartRef"/>
 </xsd:schema>