Which GUID/UUID format UE4 uses?

I’m trying to make heads and tails out of the GUID (FGUID) UE4 uses. For example this:
{E4B068ED-42E9-F494-0BDA-31A241BB462E} (12)
{guid} (version)
Does not conform to the spec RFC 4122 - A Universally Unique IDentifier (UUID) URN Namespace
It’s variant is 0 (backwards compatibility reserved) and its version is F (or 9 if we use BE) - non-existent.

As per https://github.com/EpicGames/UnrealEngine/blob/6c20d9831a968ad3cb156442bebb41a883e62152/Engine/Source/Runtime/Core/Private/Serialization/CustomVersion.cpp#L291-L296