Bit of a work in progress but we've been trying to come up with a sane way to model the specification of entitlements and how we'll enforce them for a given customer with a policy that may change.
We've landed at something like the following:
https://fedorahosted.org/candlepin/wiki/PolicyDesign
It's a bit simplified as a starting point and may still change, but at this point it's probably readable for those who are interested. Please feel free to send feedback.
Cheers,
Devan