gEdkiiWorkingBlockSignatureGuid

GUID used as the signature of FTW working block header.
Include/Guid/SystemNvDataGuid.h

GUID Information

GUID's Guid Name	GUID's Guid
gEdkiiWorkingBlockSignatureGuid	{ 0x9e58292b, 0x7c68, 0x497d, { 0xa0, 0xce, 0x65, 0x0, 0xfd, 0x9f, 0x1b, 0x95 }}

Refer to Header File

MdeModulePkg/Include/Guid/SystemNvDataGuid.h