meta tag alter question,

[indie]

I noticed the meta tags have..

<!-- no cache headers -->
<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Expires" content="-1" />
<meta http-equiv="Cache-Control" content="no-cache" />
<!-- end no cache headers -->

Now on one of the hacks (portal), I asked how to keep it from caching, but was given a 4 line of code, :

<!-- nocache headers -->
<meta content="no-cache" http-equiv="pragma" />
<meta content="no-cache" http-equiv="no-cache" />
<meta content="-1" http-equiv="expires" />
<meta content="no-cache" http-equiv="cache-control" />
<!-- end nocache headers -->

What is the difference?? The second was is a little different and includes an extra line.

Thanks!