Class 1 (Faction) Hideaway or Drone Cluster (easiest)
Class 2 (Faction) Burrow or Drone Collection
Class 3 (Faction) Refuge or Drone Gathering
Class 4 (Faction) Den or Drone Assembly
Class 5 (Faction) Yard or Drone Surveillance
Class 6 (Faction) Rally Point or Drone Menagerie
Class 7 (Faction) Port or Drone Herd
Class 8 (Faction) Hub or Drone Squad
Class 9 (Faction) Haven or Drone Patrol
Class 10 (Faction) Sanctum or Drone Horde (hardest)

Each Anomaly Class has 4 different level's ranging from Level 1 (easiest) to Level 4 (hardest).
Level 1 = (Faction name) + Anomaly Class (easiest)
Level 2 = (Faction name) Hidden + Anomaly Class
Level 3 = (Faction name) Forlorn + Anomaly Class
Level 4 = (Faction name) Forsaken

http://i.imgur.com/joSo04T.gif