Why the script tag that boots the application inserted after body tag.

WEB TMS WEB Core
1

I am sure there is some reason for this type of insertion (after body tag). Can you tell me why?
Thanks in advance
Mehmet

  <body>
  </body>
  <script type="text/javascript">
    rtl.run();
  </script>
</html>
2

I need to check with the pas2js team if there is a specific technical reason for this.