There are 7 unique codex entries in the Lore section on Korriban. 5 are faction specific and 2 are class specific.
Admission to the Sith Academy is obtained from interacting with a Clickable Holocron.
Codex type: Lore | Faction: Imperial | Class: All
Associated Achievement: Loremaster of Korriban
Legacy of Tulak Hord is obtained from interacting with a Clickable Crate.
Codex type: Lore | Faction: Imperial | Class: All
Associated Achievement: Loremaster of Korriban
Sith Titles is obtained from interacting with a Clickable Holocron.
Codex type: Lore | Faction: Imperial | Class: All
Associated Achievement: Loremaster of Korriban
Sith Weapons (inq) | Coordinates: -299, 66 | Location: Korriban: Sith Academy: Level 2
Sith Weapons (war) | Coordinates: 143, -400 | Location: Korriban: Tomb of Naga Sadow: Forbidden Cavern
Sith Weapons is obtained from speaking with Lord Zash during "A Map for the Future" mission as a Sith Inquisitor player or interacting with the Ancient Sarcophagus during "The Final Trial" mission as a Sith Warrior player. It is obtained with the Apprentice codex for Sith Inquisitors. Sith Weapons is unobtainable for Bounty Hunter and Imperial Agent characters.
Codex type: Lore | Faction: Imperial | Class: All
Associated Achievement: Loremaster of Korriban
Slavery in the Empire is obtained from interacting with a Clickable Holocron.
Codex type: Lore | Faction: Imperial | Class: All
Associated Achievement: Loremaster of Korriban
The Red Engine is obtained from interacting with The Red Engine during "[HEROIC 2+] The Hate Machine" mission as a Sith Inquisitor or Sith Warrior player.
Codex type: Lore | Faction: Imperial | Class: Sith Inquisitor & Sith Warrior
Associated Achievement: Loremaster of Korriban
The Role of a Dark Council Member (Inquisitor) is obtained from speaking with Darth Thanaton during "The Dark Council" mission.
Codex type: Lore | Faction: Imperial | Class: Sith Inquisitor
Associated Achievement: None