           <th colspan="4">General Options</th>
          </tr>
          <tr>
            <td class="popt">-f</td><td><span class="pdat">file</span></td>
            <td>Specifiy a <span class="pdat">file</span> containing a list of
              sequence identifiers.</td>
            <td>The sequence identifiers must be specified on the command line
              or on standard input.</td>
          </tr>
          <tr>
            <td class="popt">-c</td><td></td>
            <td>Check that the index act