Description of problem:
yum.conf(5) states:

  $releasever
              This will be replaced with the value of the version of the pack-
              age listed in distroverpkg. This  defaults  to  the  version  of
              ‘redhat-release’ package.

Here yum.conf says:

  distroverpkg=redhat-release

And there isn't such a package.

Plus the yum.repos.d/fedora-core.repo contains uses of $releasever, which seems
to map to "development" (is there any way to find out what the variable values
are?) for rawhide, judging from the layout at <http://download.fedora.redhat.com>

All this just doesn't add up.

Version-Release number of selected component (if applicable):
yum-3.0.1-6.fc7

How reproducible:
Has been this way for quite some time...

Steps to Reproduce:
1. Try to make sense out of the documentation ;-)
2.
3.
  
Actual results:
Utter confusion

Expected results:
Some enlightenment...

Additional info: