# 11.4. Deprecated Definitions

The PMIx Standard will occasionally decide to deprecate and subsequently remove attribute and constant definitions - and on rarer occasions, functional APIs. The OpenPMIx library, however, maintains a policy of never actually removing deprecated definitions. This is done with the intent of maintaining, to the maximum extent possible, full backward compatibility.

Deprecated definitions are moved from their original header files to the pmix_deprecated.h file to identify them as deprecated. While continuing to be valid, users are encouraged to migrate away from these definitions to remain in sync with the continued evolution of the PMIx Standard.