Here is the link:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsdk/html/xsdrefattributeelement.asp

"Han" wrote:

> Interesting example. As I read MSDN, only the name of a complexType is 
> allowed.
> 
> (Excerpt)
> 
> restriction (complexContent)
> 
> base
> The name of a complexType element defined in this schema (or another schema 
> indicated by the specified namespace). The element containing the 
> restriction element is derived from the type specified by the base value.
> 
> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/xmlsdk/html/xsdrefrestrictioncomplexContentElement.asp
> 
> Do you happened to have a link of the example?
> 
> "Mahalax" <Mahalax@d...> wrote in message 
> news:796D6E29-A336-48B7-92B9-CA8C6F73F8CD@m......
> > Yes, it does. Here is the MSDN sample.
> >
> > <xs:attributeGroup name="A">
> >  <xs:attribute name="x" type="xs:NCName"/>
> >  <xs:attribute name="y" type="xs:QName"/>
> > </xs:attributeGroup>
> >
> > <xs:complexType name="B">
> >  <xs:complexContent>
> >   <xs:restriction base="xs:A">
> >    <xs:attribute name="x" use="required" />
> >    <xs:attribute name="y" use="prohibited"/>
> >   </xs:restriction>
> >  </xs:complexContent>
> > </xs:complexType>
> >
> > -Maha
> >
> > "Han" wrote:
> >
> >> I mean reuse. I mean @use attribute at reused attributeGroup.
> >> By the way, does MSDN example use name of an attributeGroup for its @base
> >> attribute?
> >>
> >> "Mahalax" <Mahalax@d...> wrote in message
> >> news:CE54F817-01C7-487C-B277-F8245F2E0531@m......
> >> > Hi Han,
> >> >
> >> > Actually I am trying to explore the attributegroup and its purpose. 
> >> > Many
> >> > of
> >> > my schemas have a set of common atributes which I am trying to declare
> >> > commonly and reuse as required. The code I have posted is an adaptation
> >> > from
> >> > MSDN which is not working.
> >> >
> >> > "Han" wrote:
> >> >
> >> >> OOPS, I mean @use by @required in the earlier post. Values are,
> >> >>
> >> >> optional, prohibited, required
> >> >>
> >> >> "Mahalax" <Mahalax@d...> wrote in message
> >> >> news:207B477E-4686-4015-8CFE-A510B3AEBE6B@m......
> >> >> > Greetings.
> >> >> >
> >> >> > Below is the schema snippet I am trying to explore attributegroups 
> >> >> > and
> >> >> > attribute's use property. However I am getting a validation error
> >> >> > saying
> >> >> > "undefined value for base encountered", pointing to 
> >> >> > <xs:restriction>.
> >> >> > Please
> >> >> > help.
> >> >> >
> >> >> > <?xml version="1.0" encoding="UTF-8"?>
> >> >> > <xs:schema elementFormDefault="qualified"
> >> >> > attributeFormDefault="unqualified"
> >> >> > xmlns:xs="http://www.w3.org/2001/XMLSchema">
> >> >> > <xs:attributeGroup name="grp">
> >> >> > <xs:attribute name="x" type="xs:string"/>
> >> >> > <xs:attribute name="y" type="xs:string"/>
> >> >> > <xs:attribute name="z" type="xs:string"/>
> >> >> > </xs:attributeGroup>
> >> >> > <xs:complexType name="A">
> >> >> > <xs:complexContent>
> >> >> > <xs:restriction base="xs:grp">
> >> >> > <xs:attribute name="x" use="required"/>
> >> >> > <xs:attribute name="y" use="prohibited"/>
> >> >> > <xs:attribute name="z" use="required"/>
> >> >> > </xs:restriction>
> >> >> > </xs:complexContent>
> >> >> > </xs:complexType>
> >> >> > </xs:schema>
> >> >> >
> >> >> > Best Regards,
> >> >> > Mahalakshmi Natarajan
> >> >> > http://mahalax.blogspot.com
> >> >> > http://dotnetjunkies.com/weblog/mahalax
> >> >>
> >> >>
> >>
> >> 
> 
>