title: What happens if I don't specify targetFramework="4.0"?
body: <p>In my ASP.Net 4.0 web.config I had the following attribute:</p>
  
  <pre><code>&lt;compilation targetFramework="4.0"&gt;
  </code></pre>
  
  <p>If I remove the targetFramework attribute, everything appears to carry on as normal.  Under what circumstances does this attribute help me?</p>