Possible Duplicate:
shorthand as // for script and link tags? anyone see / use this before?
I think I understand what is going on but I haven't found anything definitive while googling. In code such as this:
// talking about the src attribute
<script type="text/javascript" src="//use.typekit.net/%kitid%.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js"></script>
I am used to http:// being there. When I call this page on an http server it makes a regular HTTP request for the resource so I am assuming this is a shortcut for http://. I am guessing this has to do with not knowing whether the page you are on wants to use https:// or http://? Any articles or anything that have some information on this practice?