Decade has passed and Dol Guldur never had it's unique rank names. I tried to create ranks which are fit to this faction and and potentially could be implemented in this mod.

Here:
Rank 0 Worm
Rank 1 Snaga
Rank 2 Forest Skulker
Rank 3 Gaoler of Dol Guldur
Rank 4 Dungeon Overseer
Rank 5 Defiler of Tombs
Rank 6 Watchman of Sorcery Spire
Rank 7 Keeper of Black Library
Rank 8 Commander of Dol Guldur
Rank 9 Necromancer's Right Hand