title: Consequences of including an external script file in a GTM tag
body: <p>In GTM, lets say that I have a "custom HTML" tag, and in it include an external script file like </p>
  
  <p><code>&lt;script type="text/javascript" src="http://externalsite.com/file.js"&gt;&lt;/script&gt;</code></p>
  
  <p>How is this file loaded? Does it affect the loading time of the page?</p>
  
  <p>I know that the GTM script is loaded asynchronously along with the tags, but I can't really imagine what happens in this case.</p>