title: Why does this simple XSD not validate?
body: <p>I'm trying to write my first xsd schema, and have run into an issue. I came up with the simplest XSD I could... but it doesn't validate. What am I doing wrong here?</p>
  
  <p>linux command prompt:</p>
  
  <pre><code>user@computer:~$ xmllint --valid --schema test.xsd test.xml
  &lt;?xml version="1.0"?&gt;
  &lt;!DOCTYPE configuration SYSTEM "test.dtd"&gt;
  &lt;configuration/&gt;
  test.xml:3: element configuration: Schemas validity error : Element 'configuration': No matching global declaration available for the validation root.
  test.xml fails to validate
  </code></pre>
  
  <p>test.xml</p>
  
  <pre><code>&lt;?xml version="1.0" ?&gt;
  &lt;!DOCTYPE configuration SYSTEM "rcXMLAPI.dtd"&gt;
  &lt;configuration/&gt;
  </code></pre>
  
  <p>test.xsd</p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;
  &lt;xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.w3schools.com" xmlns="http://www.w3schools.com" elementFormDefault="qualified"&gt;
  
  &lt;xs:element name="configuration"&gt;
  &lt;/xs:element&gt;
  
  &lt;/xs:schema&gt;
  </code></pre>