owncalendar/templates/part.404.php

<ul>
  <li class="error">
    <?php if (isset($_['message'])) {
      p($l->t( $_['message']) );
    } else {
      p($l->t( 'Public calendar not found' ));
    } ?><br/>
    <p class='hint'><?php if(isset($_['file'])) p($_['file'])?></p>
  </li>
</ul>