There are 8 unique codex entries in the Persons of Note section on the Imperial Fleet. They are all faction specific.
Aven Geth is obtained from speaking with Aven Geth during "The Ranken Initiative" mission.
Codex type: Persons of Note | Faction: Imperial | Class: All
Associated Achievement: None
Darth Acina is obtained from speaking with Z1-3C during "An Invitation from Darth Acina" mission.
Codex type: Persons of Note | Faction: Imperial | Class: All
Associated Achievement: None
Darth Arkous is obtained from speaking with Darth Arkous during "Forged Alliances: Part I" mission.
Codex type: Persons of Note | Faction: Imperial | Class: All
Associated Achievement: None
Lana Beniko is obtained from interacting with the Table during "Forged Alliances: Part II" mission.
Codex type: Persons of Note | Faction: Imperial | Class: All
Associated Achievement: None
Moff Orlec is obtained from interacting with Moff Orlec's Office during "Emergency Dispatch" mission.
Codex type: Persons of Note | Faction: Imperial | Class: All
Associated Achievement: None
MZ-12 is obtained from speaking with MZ-12 during "The Ranken Initiative" mission.
Codex type: Persons of Note | Faction: Imperial | Class: All
Associated Achievement: None
Salana Rok is obtained from speaking with Salana Rok during "The Ranken Initiative" mission.
Codex type: Persons of Note | Faction: Imperial | Class: All
Associated Achievement: None
Writch Hurley is obtained from speaking with Writch Hurley during "The Ranken Initiative" mission.
Codex type: Persons of Note | Faction: Imperial | Class: All
Associated Achievement: None