Default.html

<h1>Parent Template</h1>

<p><?php echo $content ?></p>

<?php print $this->block('footer') ?>

TemplateA.html

<?php 
$this->extend = 'Default.html'; 
$this->block('footer')->prefix = '<ol>';
$this->block('footer')->suffix = '</ol>';
?>

<h2>Template A content</h2>

<?php echo $this->block('footer')->start ?>
<li><a href="#">blah</a></li>
<li><a href="#">blah 2</a></li>
<?php echo $this->block('footer')->end ?>

<p>my content</p>
<?php echo $this->partial('TemplateB.html')?>

TemplateB.html

<h2>Template B content</h2>

<?php echo $this->block('footer')->start ?>
<li><a href="#">just some link</a></li>
<?php echo $this->block('footer')->end ?>

<p>my second content</p>