EFI_ACPI_6_0_NFIT_GUID_BYTE_ADDRESSABLE_PERSISTENT_MEMORY_REGION

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_GUID_BYTE_ADDRESSABLE_PERSISTENT_MEMORY_REGION = GUID(0x66F0D379, 0xB4F3, 0x4074, 0xAC, 0x43, 0x0D, 0x33, 0x18, 0xB7, 0x8C, 0xDB);

Meta