The way the script tag is closed when referring to an external script

When referring to an external script, the correct closing of the script tag is written as follows:

 
<script type="text/javascript" src="js/a.js"></script> 

There is a problem with the self-closing script (IE11, chrome 31.0, ff 25.0 are not supported) :

 
<script type="text/javascript" src="js/a.js" />