title: IIS6 serving unregistered MIME Types
body: <p>I have an IIS6 web server (on Win2003) is having a strange behavior which I guess is some undocumented "feature" ...</p>
  
  <p>It serves SVG files (extension .svg) without having it registered on the IIS metabase. It does not have the * mime type either.</p>
  
  <p>For this request:</p>
  
  <pre><code>GET /basic/file1.svg HTTP/1.1
  </code></pre>
  
  <p>the response contains</p>
  
  <pre><code>HTTP/1.1 200 OK
  Content-Length: 32817
  Content-Type: image/svg+xml
  </code></pre>
  
  <p>So ... where does IIS got this <code>image/svg+xml</code> mime type?</p>
  
  <p>The only place I found it is in Registry, at <code>HKEY_CLASSES_ROOT\MIME\Database</code>.
  But according to all the MS information I found, the source for IIS allowed mime types is it's own metabase.</p>
  
  <p>Does anyone know this behavior? This could lead a IIS admin to a false sense of security...</p>
  
  <p>Best regards everyone!!</p>