Part of lp.registry.interfaces
| Class | EntitlementQuotaExceededError | The quota has been exceeded for the entitlement. | 
| Class | EntitlementInvalidError | The entitlement is not valid. | 
| Class | EntitlementType | The set of features supported via entitlements. | 
| Class | EntitlementState | States for an entitlement. | 
| Interface | IEntitlement | An entitlement the right to use a specific feature in Launchpad. | 
| Interface | IEntitlementSet | Interface representing a set of Entitlements. | 
| Class | EntitlementQuota | This class stores constants for entitlements quotas. |