title: PHP: When submitting an HTML form, does the HTTP_REFERER get set?
body: <p>An exception was thrown in my application, but the HTTP_REFERER was null, which seems strange in this case. I'm wondering if you could answer a quick question: </p>
  
  <p>So I've got this form:</p>
  
  <pre><code>&lt;!-- mysite.com/index.html --&gt;
  
  &lt;form action="http://mysite.com/somewhere/else"&gt;
      &lt;input type="submit" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>When someone submits the form, I am expecting that the <code>$_SERVER['HTTP_REFERER']</code> will be set to <code>/index.html</code>. Is that true?</p>