EFI_ACPI_6_0_NFIT_MEMORY_DEVICE_STATE_FLAGS_PREVIOUS_SAVE_FAIL

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
extern (C)
enum EFI_ACPI_6_0_NFIT_MEMORY_DEVICE_STATE_FLAGS_PREVIOUS_SAVE_FAIL = BIT0;

Meta