From Lexicanum

Librarian

Lexicanium - Codicier - Epistolary - Chief Librarian

Epistolary is the third rank of Space Marine Librarians. Their primary role is chief communications officer, both on the battlefield and beyond.¹ They are able to use their powers to project their mind through the warp, similar to the Astropaths of the Adeptus Astra Telepathica, but without the need to endure the torturous ritual of soul binding that is otherwise required. More commonly, their abilities are used over shorter distances, coordinating attacks and battle orders.³

In 4th and 5th editions, Epistolaries are the more powerful of the choices available to a Space Marine force.²

Sources

• ¹:Genestealer (1990, Space Hulk expansion)
• ²:Codex: Space Marines (4th Edition)
• ³:Index Astartes I - Psykana Librarius Space Marine Librarians

Space Marine Infantry

Command	Master • Captain • Master of Sanctity • Reclusiarch • Epistolary • Codicier • Command Squad • Apothecary • Company Standard Bearer • Company Champion
Standard	Tactical • Assault • Devastator • Scout • Veteran • Tyrannic War Veterans • Honour Guard
Terminators	Terminator Squad • Terminator Assault Squad • Terminator Command Squad