Open32 return codes are currently not guaranteed to be mapped to the same return codes that Windows returns for the same errors. In most cases, this should be acceptable because the set of OS/2 errors is generally a superset of the Windows NT errors. Virtually all of the OS/2 error codes map directly to the identical Windows NT error code. OS/2, however, has several additional error codes that Windows NT does not. These error codes provide more precise information about the cause of the failure.