title: What is this XSD import namespace for?
body: <p>I have an xsd document that starts with:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"&gt;
      &lt;xs:import namespace="http://www.w3.org/XML/1998/namespace"     schemaLocation="http://www.w3.org/2001/xml.xsd"/&gt;
      &lt;xs:complexType name="T_segment"&gt;
          &lt;xs:sequence&gt;
              &lt;xs:element ref="element" maxOccurs="unbounded"/&gt;
          &lt;/xs:sequence&gt;
          &lt;xs:attribute ref="xml:space" use="required"/&gt;
          &lt;xs:attribute ref="id" use="required"/&gt;
      &lt;/xs:complexType&gt;
  ...
  </code></pre>
  
  <p>When I try to use this xsd in a mapping application like BizTalk it blows up complaining about namespaces.  So, I remove the xs:import namespace tag and it complains about the xs:attribute ref="xml:space" tag.  So, I remove that and it seems to work ok (at least doesn't blow up).</p>
  
  <p>My question is, what are those tags for?  By removing them am I breaking the xsd?</p>
  
  <p>From what I know namespaces are to avoid conflicts.  But in the xsd everything is prefixed by xs and the schema itself has xmlns:xs="http://www.w3.org/2001/XMLSchema".  I'm not sure what that import is for.</p>