Use of a CSS stylesheet url with parameters

Question

What are the parameters in a stylesheet uri used for? For instance, Dell's main page has this link with three parameters:

<LINK REL="STYLESHEET" TYPE="text/css" HREF="http://www-cdn.dell.com/content/public/css.aspx?c=us&l=en&~set=storm81_hp">

I know that a single parameter when changed can be used to force browser to re-fetch the stylesheet. Eg:

eg: http://sstatic.net/stackoverflow/all.css?v=a6754691e23a

but the Dell link is obviously aiming at sending the params back to the server for processing. Is this used to select a specific version of a stylesheet? In that case why not send the targeted stylesheet in the first place?

Wondering...

Answer 1

they're using a script to generate their CSS file so the file is not a static .css file

basically the serverside behind the aspx file (could be C# or VB.net) outputs as mimetype text/css