there is no match, an HTML
          <span class="QUOTE">"BLOCKED"</span> page is sent back to the browser. Otherwise, if it does match, an image
          is returned for the former, and an empty text document for the latter. The type of image would depend on the
          setting of <a href="actions-file.html#SET-IMAGE-BLOCKER"><span class="QUOTE">"+set-image-blocker"</span></a>
          (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).</p>
        </li>
        <li>
          <p>