Editing Codex Astartes (section)

===Other Departments===
Outside of the above mentioned battle ranks, there are other positions within a Chapter:

====Librarium====
A chapter may have any number of [[Librarian]]s, with no Codex-mandated minimum or maximum. The fact that psykers, let alone Astartes psykers, are rare makes the position self-limiting. Can use the standardized Librarian Discipline, Chapter specific disciplines or generic [[Psychic Disciplines]] like Biomancy, Pyromancy, Telekinesis, Telepathy, Technomancy or Divination to name a few.
*'''Chief Librarian''': The head of the Librarium, who assigns [[Librarian]]s to assist in battlefield communications. He is also tasked to determine whether or not his battle-brothers are tainted by [[Chaos]].
*'''Epistolary:''' The highest rank below Chief Librarian, Epistolaries serve as the main communication aides on the battlefield.
*'''Codicier:''' Mid-level Librarians who evaluate reports from campaigns and document them in their Librariums.
*'''Lexicanum:''' Entry-level Librarians responsible for compiling battlefield reports for the Codiciers.
*'''Acolytum:''' Neophytes who have been identified as psykers.
*'''[[Vanguard Librarian]]:''' Primaris Librarian assigned to Vanguard duty. Trained in the special Obscuration discipline.

====Apothecarion====
A chapter may have any number of apothecaries, although the Codex mandates at least 11 (one per Company, plus the Chief Apothecary).

*'''Master of the Apothecarion''': The head of the Apothecarion, who assigns an [[Apothecary]] to each Company. The Apothecarion in turn also takes care of the [[gene-seed]] that Chapters place such holy emphasis on, for good reason: no gene-seed = no new recruits.
*'''[[Apothecary]]''': Responsible for medical care, biological and genetic research, and the critically important harvesting of gene-seed from Battle Brothers and the cultivation of said gene-seed.
*'''[[Primaris_Apothecary#Helix_Adept|Helix Adept]]:''' Apprentice Primaris Apothecaries assigned to [[Infiltrator]] squads.

====The Chaplaincy/Reclusium====
A chapter may have any number of chaplains, although the Codex mandates at ''least'' 11 or 12 if fully staffed (One per Company, plus the Reclusiarch/Master of Sanctity).
*'''Master of Sanctity''': The head of the Chaplaincy and spiritual leader of the Chapter. He assigns [[Chaplain]]s to the Companies to oversee the spiritual health of the Chapter. This position is often but not always held by the chapter's Reclusiarch. Though it might be tempting to compare them to warrior bishops, they're actually atheists (save some Chapters closely aligned to the [[Ecclesiarchy]] or the [[Mechanicus]]), seeing the Emperor as an honored predecessor and the epitome of humanity but not a god.
*'''Reclusiarch''': The Chaplain who oversees the Chapter's Reclusiam (where they keep the relics and other secret historical stuff). Often the job gets rolled up into the Master of Sanctity's job description (particularly if the Chapter is relatively young and has not accrued entire millennia worth of trinkets). It's uncertain what interaction (if any) they have with the Master of Relics; it is quite possible that a Chaplain receives the role if that Captain of the 9th company gets a different position. It is possible that the Reclusiarch looks after the more "holy" and historically significant relics, distributing some of them to Chaplains to carry in battle, while the Master of Relics okays the deployment of precious but combat-worthy stuff like ancient marks of power armour or Heresy-era tanks (Master of the Forge is technically a specialist position, not an authoritative one).
*'''[[Chaplain]]''': Ministers to the psychological stability of their brothers, inspiring them and allied forces in battle and watching for Chaos corruption.
*'''[[Judiciar]]''': Primaris Chaplains in training equipped with Executioner Blades and Tempormortis temporal distortion devices, charged with enforcing the Chapter Master's will.

====Armoury/Armorium====
A Chapter's armoury consists of any number of [[Techmarine]]s and dedicated vehicle operators who do not formally get assigned to any Company. In practice, techmarines tend to form a distinct clique within their chapters; partly due to their idiosyncrasies, and partly because they have a dual loyalty to Mars.
*'''Master of the Forge''': The head of the Armoury, who assigns [[Techmarine]]s to oversee maintenance of the machine-spirits of the chapter's wargear and motor pool. Their position often overlaps to some degree with the Chapter's Reclusiarch, given that both are responsible for keeping the chapter's relics in good condition; many artifacts will fall under both of their duties. Given that their religious zeal is tempered by the practical mindset of a space marine, Masters of the Forge are some of the only engineers in the galaxy that are actually still innovating to any degree, which really shows when you compare the armories of the modern space marine chapters with their traitorous counterparts.
*'''[[Techmarine]]''': As with the Apothecaries, one per company and the Master of the Forge plus others is a frequent arrangement; otherwise they are deployed as needed to operate advanced war gear or lend technical expertise at battle. When not in the field they repair or produce arms, equipment, vehicles and other supplies along with Chapter Serf Artificers and any Tech Priests assigned to the Chapter.
*All Space Marines are required to familiarise themselves with operation of Rhino tanks at the very least as part of their standard training.
**Drivers of the armoury vehicles are referred to as '''Custodians''' (unrelated to the [[Adeptus Custodes]]), many of whom are assigned when necessary from the squads of the 6th & 7th reserve companies. They are expected to continue their development through the companies and learn ''every'' aspect of war so that vehicle commanders better anticipate the roles of Tactical/Assault/Devastator and provide battlefield support without even being requested - unless they get assigned to the armoury on a more permanent basis, such as being trained to operate larger, more precious vehicles and/or specialising in armoured operations.
**Battlefield support vehicles tend not to be assigned permanent crews but are manned by individuals capable of operating a number of chapter vehicles, helped in part to the ubiquity of the Rhino chassis and the standard training.
*Dreadnoughts are typically assigned back to their original companies and appear sporadically across a chapter's roster, though some chapters assign Dreadnoughts to their own formations instead. The technology to build even the most basic dreadnought is rare and time-consuming even for master artificers, so the number is limited; also the frequency of wakefulness decreases over time and they get used less and less.

====The Fleet====
A chapter is allowed a fleet of as many ships as it can get together, and may assign Marines to these ships as permanent staff in a similar fashion to the Armoury, although the Codex is significantly more flexible on Fleet staff. A chapter can be Codex-compliant without any Marines in their Fleet at all. Ship designations made for Space Marines have a fairly narrow band of marine transport capacity - one to three companies' worth - which does not change significantly between chapters. Therefore while a chapter could theoretically muster a fleet of any size, the practical and political restraints limit a chapter fleet's size. At the top end, the best is a [[Battle Barge]] for each company, another Battle Barge for a flagship and accompanying [[Strike Cruiser]]s, [[Adeptus Astartes Light Cruiser|Light Cruisers]] and [[Adeptus Astartes Escort|Escort]]s, plus whatever orbital defenses of the homeworld and the system fleet and maybe one or two mobile stations. This is stretching it for most chapters, though ancient and politically secure can have more than this and some chapters have different classes of ship as well. The Navy frowns upon Marines having too many [[Lance Weapon|Lance]]-equipped ships in particular. Fleet based Chapters obviously have more than usual, and one powerful vessel, possibly even a Warp-capable Star Fort, serves as the Fortress-Monastery.

*'''Master of the Fleet''': Often the Captain of the 4th company gets this position by default, but as mentioned above in the entry for Fourth Captain it's [[Uriel Ventris|not unheard of for a Captain to step down]] from the position if someone else would be better suited to the role: that person is titled "Lord Admiral" and gets command over the Chapter's fleet assets. It is perfectly reasonable that the Lord Admiral holds a battlefield rank of Battle-Brother or Sergeant, making him probably temporary until the Captain or his replacement wants the job back. As mentioned above, some Chapters (especially fleet-based ones) have this post be straight-up separate from the role of Fourth Company captain and have a dedicated full-time Marine as Master of the Fleet in the Chapter Council while the Fourth Captain gets different special roles.
*'''Lieutenant Commander''': In the days of the Great Crusade, these individuals commanded battalions of five companies, outranking Captains and subservient to Chapter Masters. We know of [[Marines Errant|only one example]] of this rank though it is uncertain whether the title holds the same authority as before. From what we know it now applies to the commander of a vessel, which makes sense since most Space Marine chapters have more ships than Captains, so ''somebody'' has to get the job of commanding them. Often assumed to be just a techmarine or sergeant of whichever squad gets attached to that vessel, or more likely a badass high ranking [[Chapter Serf]] who doesn't need to be superhuman to understand how spaceships operate. 
**With the advent of the company rank of Lieutenant, it is uncertain as to how the Lieutenant Commander actually fits in the new command structure. Is it a superior form of Lieutenant with new duties (which is what the rank itself implies) or is it a Lieutenant who has been officially combined with the Force Commander role (see above) and has his own units set aside from his company that he commands on a full time basis? More likely, considering that Space Marines tend to hold to an army chain of command rather than a naval hierarchy, the rank is probably an honorific title that stands alongside their company rank as with the Lord Admiral. It is also quite possible this is now the same as a old ''naval'' Lieutenant Commander, which was a ''Lieutenant'' serving as the ''Commander'' of a vessel.