title: Do dynamic responses (PHP, Django, etc) set any sort "not static" variable in the response header?
body: <p>If I have some site on a server:</p>
  
  <pre><code>//hello.html
  &lt;html&gt; hello &lt;/html&gt;
  </code></pre>
  
  <p>Would all of the following be requested and/or cached individually:</p>
  
  <p><code>http://hello.html</code>, <code>http://hello.html?place=world</code>, <code>http://hello.html?foo=bar</code></p>
  
  <p>...even though they are the same result?</p>
  
  <p>Is there some variable in the header that denotes the difference between a static (always the same) response to a request and one which has had some meddling (ie. PHP, templates)?</p>
  
  <p>EDIT: if the site was (I don't know PHP):</p>
  
  <pre><code>&lt;html&gt;&lt;?php
     print "hello"+$_GET['place'];;
  ?&gt;&lt;/html&gt;
  </code></pre>
  
  <p>the results would be different for the three urls:</p>
  
  <p><code>http://hello.html</code>, <code>http://hello.html?place=world</code>, <code>http://hello.html?foo=bar</code></p>
  
  <p>Is the response header also changed to express that for all three the page is not static (not cacheable)?</p>