'''Lexicanium''' is the lowest rank of [[Space Marine]] [[Librarian]]. This rank is given to those who have recently joined the [[Librarius]] and are given duties surrounding the creation of battle reports to submit to the Chapter's records.¹ ³ These summary accounts chronicle the history of a [[Chapter|Chapter]] and can vary in nature, depending on the Lexicanium's]] recordsbeliefs and philosophy or the campaign.¹³  Lexicanium Librarians are often distinguished by their lack of a [[psychic hood]] or even helmet, appearing very similar to their brother-marines except for the blue [[Power Armour]] that Librarians wear.²