title: Strange encoding of non-ASCII character in URL
body: <p>My mother recently received the following scam message on Whatsapp (I have added multiple extra m's to the end of the link below in case of accidental clicks. Obviously the original link itself ended only with <code>.com</code>):</p>
  
  <blockquote>
    <p>British Airways is giving free 5000 tickets to celebrate its birthday. Get your free ticket at : <a href="http://www.bri%E1%B9%ADishairways.commmmmmmm/" rel="nofollow noreferrer">http://www.briṭishairways.commmmmmmm/</a></p>
  </blockquote>
  
  <p>It seems to be a legitimate link to the British Airways URL, especially since Whatsapp doesn't allow link obfuscation (i.e. sending someone to SO by clicking <a href="http://www.stackoverflow.com">http://www.google.com</a> isn't possible).</p>
  
  <p>However, a careful look will show that the <code>t</code> is in fact a <code>ṭ</code> (<a href="https://en.wikipedia.org/wiki/%E1%B9%AC" rel="nofollow noreferrer">Latin T with dot below</a>). Also, if one either hovers the mouse over the link in Chrome, the URL that appears at the bottom-left corner of the screen is in fact <a href="http://www.xn--briishairways-rt1g.commmmmmmm/" rel="nofollow noreferrer">http://www.xn--briishairways-rt1g.commmmmmmm/</a>. This is also the output from doing a right-click&nbsp;>&nbsp;Copy Link Address. (Try it yourself!)</p>
  
  <p>Also, if I edit the body of the link, the <code>rt1g</code> part changes, as if it's a counter for where to put the dot. For example:</p>
  
  <ul>
  <li>briṭishairways = xn--briishairways-rt1g</li>
  <li>briṭishairway = xn--briishairway-vk5f</li>
  <li>riṭishairway = xn--riishairway-yb9e</li>
  <li>rṭishairay = xn--rishairay-5s6d</li>
  </ul>
  
  <p>What's especially odd is that the Wikipedia link I used for <a href="https://en.wikipedia.org/wiki/%E1%B9%AC" rel="nofollow noreferrer">Latin T with dot below</a> also uses the same character (well, the capitalized version of it), and the URL shown on mouse-hover does not have this effect. (Try it yourself!)</p>
  
  <p>What is going on here?</p>