There are 6 flags, essentially.
You get all 6, you are in void G. 5 you are in void F. Etc.
The flags are OGH (either raid or grp), Kith (raid or grp), FOS (raid or grp), Rathe (raid or grp), Kora/BF (raid or grp), and Discord Tower (raid).
Additionally, to get Korafax access, you have to do the first 4 of those either "all grp" or "all raid".