title: Use a base64 embedded image multiple times
body: <p>I have a couple small images in an HTML document that I want to make portable, e.g. still works when emailing. I use the following, which works great:</p>
  
  <pre><code>&lt;img src="data:image/png;base64,..."/&gt;
  </code></pre>
  
  <p>Problem is, I want to use the same image many times in the document, but don't want to repeat the entire base64 data string. I have seen in emails where the data is encoded a single time, but referenced many. Is this possible with HTML?</p>