title: Animated icon in email subject
body: <p>I know about <strong>Data URI</strong>s in which <a href="http://en.wikipedia.org/wiki/Base64"><code>base64</code></a> encoded data can be used inline such as images. Today I received an email actually an spam one in which there was an animated (gif) icon in its subject:</p>
  
  <p><img src="https://i.stack.imgur.com/AHP8U.jpg" alt="enter image description here"></p>
  
  <p>Here is the icon alone:</p>
  
  <p><img src="https://i.stack.imgur.com/zrSN6.gif" alt="enter image description here"></p>
  
  <p>So the only thing did cross my mind was all about Data URIs and if Gmail allows some sort of emoticons to be inserted in subject. I saw the full detailed version of email and pointed to subject line at the below picture:</p>
  
  <p><img src="https://i.stack.imgur.com/5fKt1.jpg" alt="enter image description here"></p>
  
  <p>So GIF comes from <code>=?UTF-8?B?876Urg==?=</code> encoded string which is similar to Data URI scheme however I couldn't get the icon out of it. Here is element HTML source:</p>
  
  <p><img src="https://i.stack.imgur.com/ltVjN.jpg" alt="enter image description here"></p>
  
  <p>Long story short, there are lots of emoticons from <code>https://mail.google.com/mail/e/XXX</code> where <code>XXX</code> are hexadecimal numbers. They are documented nowhere or I couldn't find it. If that's about Data URI, so how is it possible to include them in Gmail's email subject? (I forwarded that email to a yahoo email account, seeing <code>[?]</code> instead of icon) and if it's not, then how that encoded string is parsed?</p>