Classification Scheme

Private 

Not for direct use by customers. May change or be removed in any release. 

Evolving 

For use by customers. Subject to incompatible change at a major (e.g. 3.0, 4.0) or minor (e.g. 3.1, 3.2) release. The changes will be made carefully and slowly. Reasonable efforts will be made to ensure that all changes are compatible but that is not guaranteed. 

Stable 

For use by customers. Subject to incompatible change at a major (for example, 3.0 or 4.0) release only. 

Standard 

For use by customers. These interfaces are defined by a formal standard, and controlled by a standards organization. Incompatible changes to these interfaces are rare. 

Unstable 

For use by customers. Subject to incompatible change at a major (e.g. 3.0, 4.0) or minor (e.g. 3.1, 3.2) release. Customers are advised that these interfaces may be removed or changed substantially and in an incompatible way in a future release. It is recommended that customers not create explicit dependencies on unstable interfaces.