Need help to understand using external schemas.

[Vadim Solonovich <vs...@park.ru>]

Dear All !

Could anybody help me understand how can I  use the features from XML/Xpath/Xlink/Xpointer or other schemas ? 

1.How can I correctly import element definfitions and type declarations from those schemas ? 
As a a test I've tried to import attribute type xml:lang from XML namespace. 
The following very simple example failed with the error:

Schema error: Globally-declared attributes containing values MUST have "use" present and set to "FIXED" or "DEFAULT" 

sample.xsd:

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd='http://www.w3.org/2000/10/XMLSchema'
   xmlns:xml='http://www.w3.org/XML/1998/namespace' >

<xsd:import namespace="http://www.w3.org/XML/1998/namespace" 
  schemaLocation="http://www.w3.org/2000/10/xml.xsd"/> 

 <xsd:element name="faq">
  <xsd:complexType>
   <xsd:simpleContent>
    <xsd:extension base="xsd:string">
     <xsd:attribute ref = "xml:lang" /> 
    </xsd:extension>
   </xsd:simpleContent>
  </xsd:complexType>
 </xsd:element>
</xsd:schema>

What am i doing wrong ?

2.  Which value should I use in schemaLocation attribute for 
- XLink ?
- XPointer ?
- XPath ?
- other XML related ?


Thanks in advance,
    Vadim Solonovich