_ETW_GUID_TYPE

Windows 10 1909 (November 2019 Update, Titanium R2)
Windows 10 2004 (May 2020 Update, Vibranium R1)
Windows 10 20H2 (October 2020 Update, Vibranium R2)
//0x4 bytes (sizeof)
enum _ETW_GUID_TYPE
{
    EtwTraceGuidType = 0,
    EtwNotificationGuidType = 1,
    EtwGroupGuidType = 2,
    EtwGuidTypeMax = 3
};