Lexicanium Codicier Epistolary Lexicanium Codicier Epistolary Arcane symbols are used for the Librarian rank badges and decorate their back banners. These are references to the ancient rituals that bind the psyker to the Emperor and to his Chapter. The scrolls and books are symbols of the protective wards and mental disciplines that give the Marine the fortitude to face the perils of the Warp and remain unscathed by the horrors within. These banners show the Ultramarines variants of the traditional designs. Other Chapters simply substitute their own Chapter icon in place of that of the Ultramarines. The tabards carry additional rank markings.

The Librarians are organised separately from the Companies of the Chapter. They form the Librarius part of the Chapter Headquarters. Within its cloisters the Librarians perform their sacred and arcane duties. These are the Chapter's psykers and have many responsibilities including intersetellar communication, auguries, testing new recruits for psychic abilities and protecting the Chapter from psychic assault. They are also trained to use their awesome powers on the battlefield, attacking foes with blasts of pure thought as well as sensing enemy movements and predicting the ebb and flow of the battle. The Librarians are the ultimate warrior mystics endowed with powers and abilities that set them apart from their brothers.

The Codex has strict guidelines for the uniforms, behaviour and tactics of the Librarians. Librarians of all Codex Chapters wear blue armour with golden yellow tabards or robes. They are ranked by talent and experience, graduating from Lexicanium (novitiate rank) through Codicier to Epistolary. At the head of the Librarius sits the Chief Librarian who answers directly to the Chapter Master and is one of the leading officers of the Chapter. The Chief Librarian bears the rank and badges of Senior Epistolary.

Librarians perform an heroic role on the field of battle and have many honours bestowed on them by the Chief Librarian and their Marine brothers. Their armour, weaponry and banners are frequently embellished by the Chapter's artificers to proudly display these honours and means that no two Librarians are likely to look the same.

Ultramarines Epistolary in Terminator armour

Ultramarines Lexicanium

Imperial Fists Codicier