title: "...?ecver=x..." parameter on the youtube embed URL
body: <p>I've Noticed when embedding Youtube videos the following 2 URLs achieve the same result:</p>
  
  <p><code>https://www.youtube.com/embed/ML1AyQC2HKM?ecver=2&amp;modestbranding=1&amp;rel=0</code><br />
  <code>https://www.youtube.com/embed/kwdRYaBUco4?modestbranding=1&amp;rel=0</code></p>
  
  <p><a href="https://i.stack.imgur.com/uoON0.gif" rel="noreferrer">embeded youtube video with parameter set</a></p>
  
  <p>What does the <code>ecver</code> parameter on the youtube embed URL set ?</p>
  
  <p>After checking <a href="https://developers.google.com/youtube/player_parameters" rel="noreferrer">The Documentation</a> and searching the internet I couldn't seem to find anything to explain this parameter.</p>
  
  <p>The name would suggest its setting the <em>Ecmascript version</em>? but this is just a stab in the dark and i can't seem to find anything to confirm this.</p>