Glossary
Entitlement
An entitlement is what a principal is currently allowed to use or access, checked at the moment of use — a status that's distinct from whatever transaction, purchase, or grant originally established it. A purchase happens once; the entitlement it produces has to be checked repeatedly, every time the access is actually exercised, and can change independently of the original transaction through renewal, expiry, or explicit revocation.
Treating the original transaction as if it were a permanent, self-enforcing grant is a common and consequential mistake: entitlements need active tracking and enforcement at the moment of use, not just a one-time record that a purchase happened at some point in the past.