title: Can create culture for en-EN on local dev machine
body: <p>I just deployed our application to our azure staging environment and ran into an issue with the <code>en-EN</code> culture not being supported. After some digging I find out that there is no such culture, and I should use <code>en-GB</code> or <code>en-US</code>instead.</p>
  
  <p>But, now to my question. On my local development machine I've got no problems creating a <code>CultureInfo</code> with <code>en-EN</code>.</p>
  
  <pre><code>CultureInfo ci = new CultureInfo("en-EN"); 
  Console.WriteLine("culture: "+ ci.ThreeLetterISOLanguageName);
  </code></pre>
  
  <p>Outputs <code>culture: eng</code></p>
  
  <p>I also tried enumerating all cultures with <code>CultureInfo.GetCultures(CultureTypes.AllCultures);</code> and there's no corresponding <code>en-EN</code> culture in the result.</p>
  
  <p>So, what's going on, why can I create a culture which shouldn't exist?</p>