it is used to embed gist to an asynchronously-loaded web pages.
<iframe
width="100%"
height="350"
src="data:text/html;charset=utf-8,
<head><base target='_blank' /></head>
<body><script src='https://gist.github.com/Albert-W/e37d1c4fa30c430c37d7b1b1fe9b60d8.js'></script>
</body>">
Awesome! Just what I need right now 👍
Thanks