anchor.diff:          story text</td>
       </tr>
     <% end %>
  -
     </table>
   </div>
  
positive.code:   text</pre></td>
      <td>prefix text with at least<tt>&nbsp;&nbsp;&nbsp;&nbsp;4 spaces</tt></td>
    </tr>
  
    <% if defined?(allow_images) && allow_images %>
      <tr>
        <td>(inline image)</td>
  
negative.code:   <tr>
      <td><strike>struck-through</strike></td>
      <td>surround text with <tt>~~two tilde characters~~</tt></td>
    </tr>
    <tr>
      <td><tt>fixed width</tt></td>
      <td>surround text with <tt>`backticks`</tt></td>
    </tr>
    <tr>
      <td><a href="http://example.com/"
  