title: Information on the .MI File Extension?
body: <p>I recently noticed the .mi file extension in the url "<a href="http://www.marriott.com/default.mi" rel="noreferrer">http://www.marriott.com/default.mi</a>". It spawned some questions:</p>
  
  <ol>
  <li>What does "MI" stand for?</li>
  <li>Where is it used? What programs IO this file?</li>
  <li>How is the file used in website production?</li>
  </ol>