Documentation for syntax: mirrorlist=http://...?..& ?

On Tue, 18 Dec 2007, tom campbell wrote:

> I can't seem to find the documentation for the syntax for the following
> line in a *.repo file:
>
> mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
>
> Before I download the yum source and look at the code, I was hoping
> someone could point me to a URL/man page/ that explains:
>      * The '?'
>      * The '&'
>      * All the '='s

RFC1738