[SLL] yum repos and the mysterious life of releasever

[xeno at eskimo.com]

I'm trying to get a handle on yum repos and after over an hour looking through
Google for good instructional documents have found myself very unsatisfied.
Has anyone a recommendation for a good doc with examples on making detailed
customized yum repos, and perhaps that explain reasonably and clearly where
in the name of the redhatter gremlin gods the releasever variable is actually
set, and perhaps some nice clear and easy to use command to get the value
from simply and reliably?

xc