title: Drupal 7 - Where can I find templates for render() function?
body: <p>While I was creating my custom template for node, I found out that Drupal adds extra html.</p>
  
  <p>so I changed page.tpl.php like below to test</p>
  
  <pre><code>&lt;div style='height:300px'&gt;
    &lt;?php print render($page['content']); ?&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>and then changed node.tpl.php to</p>
  
  <pre><code>hello
  </code></pre>
  
  <p>the output is:</p>
  
  <pre><code>&lt;div style='height:300px'&gt; 
      &lt;div class="region region-content"&gt; 
      &lt;div id="block-system-main" class="block block-system"&gt; 
  
  
    &lt;div class="content"&gt; 
      hello  &lt;/div&gt; 
  &lt;/div&gt; 
    &lt;/div&gt; 
  &lt;/div&gt; 
  </code></pre>
  
  <p>where do all those extra tags come from?</p>
  
  <p>I actually expected <code>&lt;div style='height:300px'&gt;hello&lt;/div&gt;</code></p>