There are nevertheless some insightful statements by [[Games Workshop]]on the subject matter. In an older version of their FAQ section [[Black Library]] included the following answer to the question if their material was "canonical":

|quote = "''"Is Black Library fiction canon background material?''<br>''The BL editors work with the GW studios to keep the fiction the way that it should (very hard might I add! - RK), though due to the sheer volume of detail involved there can be the odd discrepancy here and there. If you want to consider anything "canonical" then both BL fiction - be it novel, graphic novel, art or background book - and GW fiction - be it White Dwarf, Codex, Army book or rulebook - are such.''

''Keep in mind Warhammer and Warhammer 40,000 are worlds where half truths, lies, propaganda, politics, legends and myths exist. The absolute truth which is implied when you talk about "canonical background" will never be known because of this. Everything we know about these worlds is from the viewpoints of people in them which are as a result incomplete and even sometimes incorrect. The truth is mutable, debatable and lost as the victors write the history ...'''''"<br>Source: [https://web.archive.org/web/20080519190316/http://forum.blpublishing.com/forum_posts.asp?TID=71 Black Library:FAQ] ''(saved archive page, dated 19 May 2008, last accessed 15 April 2020)''|align = center|width = 75em}} [[Marc Gascoigne]], Publisher and General Manager of [[Black Library]] from 1997 till 2008, was even more explicit on the vagueness of the material published. And although he marked it as his personal take on things there is not much doubt that his view would have carried some considerable weight for the authors under his supervision: {{QuoteBox|quote = "''I think the real problem for me, and I speak for no other, is that the topic as a "big question" doesn't matter. It's all as true as everything else, and all just as false/half-remembered/sort-of-true. The answer you are seeking is "Yes and no" or perhaps "Sometimes". And for me, that's the end of it.''<br>''Now, ask us some specifics, eg can Black Templars spit acid and we can answer that one, and many others. But again note thet [sic] answer may well be "sometimes" or "it varies" or "depends".''<br>''But is it all true? Yes and no. Even though some of it is plainly contradictory? Yes and no. Do we deliberately contradict, retell with differences? Yes we do. Is the newer the stuff the truer it is? Yes and no. In some cases is it true that the older stuff is the truest? Yes and no. Maybe and sometimes. Depends and it varies.''<br>''It's a decaying universe without GPS and galaxy-wide communication, where precious facts are clung to long after they have been changed out of all recognition. Read A Canticle for Liebowitz by Walter M Miller, about monks toiling to hold onto facts in the aftermath of a nucelar war; that nails it for me. [...]''<br>''To attempt answer the initial question: What is GW's definition of canon? Perhaps we don't have one. Sometimes and maybe. Or perhaps we do and I'm not telling you.''<br>''Marc Gascoigne''<br>''Publisher, BL Publishing''"<br>Source: [https://web.archive.org/web/20080522170309/http://forum.blacklibrary.com/topic.asp?TOPIC_ID=8630#136307 Black Library forums: Black Library Products and Discussion: The question of "canon"?] ''(saved archive page, dated 22 May 2008, last accessed 15 April 2020)''|align = center|width = 75em}} In a lengthy but very worthwhile interview with [https://www.boomtron.com/ Boomtron] [[Black Library]] author [[Aaron Dembski-Bowden]] had (amongst many other interesting things) the following to say on the concept of "canon" : {{QuoteBox|quote = "''There’s a reason no one ever agrees about Warhammer 40,000, even within the sheltered structures of the fandom, but it’s something so obvious that very few people end up noticing it. One of those “can’t see the wood for the trees” deals, if you get me.''<br>''The reason no one ever agrees about this stuff is because of something I like to call “loose canon.”''<br>''Canon (and its incestuous cousin, continuity) is a bit of a bitch in fictional universes. It’s something a lot of fans feel ferociously passionate about, seeing it as the glue that binds it all together, bringing forth sense from the madness. It’s also occasionally considered a badge of honour to know more than “the other guy” in certain circles [...]''<br>''“It’s all real, and none of it’s real.”''<br>''One of the great mistakes made by almost every fan of Warhammer 40,000 is to take the canonical rules of another license, and crowbar them into 40K. Usually, it’s an unconscious assumption based on a mix between common sense and Star Wars, which is a combination you don’t expect to see everyday. It also works about as well as you’d think.''<br>''Part of the problem is that 40K lore is essentially divided into 3 sub-companies all producing material, and as with all things, quality, themes, perceptions and intentions can be completely different. Games Workshop produces the games and core setting lore, with 30ish years of history, releasing a couple of sourcebooks a year. Black Library is the publishing arm, mostly centred on novels, and still very new in terms of producing canon. The third is Forge World, an allied design studio and miniature production company.''<br>''Note: An even more recent addition is Fantasy Flight Games, who produce the 40K roleplaying game, but even now, I’m not sure just where they stand. Like I said, this is a complicated hellhole of treachery, madness and deceit. As it stands, the official line is that there are three factions empowered to “create IP” (an exact quote), and that’s GW, BL and FW. Given that the 40K RPG is mostly made by folks working in or around the main three companies, I think it’s fair to say that its lore counts as canon, too.''<br>''I got it wrong myself, right up until I was in a meeting with the company’s Intellectual Property Manager – a situation I find myself in several times a year, as part of the Horus Heresy novel series team. When I was specifically asking about canon, he replied with something I’ve tried to take to heart: “It’s all real, and [n]one of it’s real.”''<br>''It was a bit of an epiphany, to tell you the truth. [...]''<br>''In short, the belief is usually that the design studio has precedence, and everything else isn’t canon. That’s actually wrong, but several aspects reinforce the misjudgement, not least that a few top brass quotes have been poorly phrased or taken out of context; some novelists wildly diverging from the source material for reasons apparent to no one but themselves; and the fact that the design studio has 30 years of history where it was essentially the sole source of canon. Its products are the foundation for the whole license – it’s the source, the core, the chewy nougat centre at the heart of it all. With the weight of history and its place as by far the most widespread, its published lore reaches the most eyes and ears.''<br>''I don’t begrudge that. In fact, in 98% of situations, I do my level best to cleave to whatever design studio sourcebook ties into what I’m writing. I’m an unashamed fanboy (you should see me fall to gleeful pieces in Horus Heresy meetings…), and I’ve spent 20 years loving the 40K universe. I’m in this to add to it, to explore it, to tell stories within it – not to change it to Hell and back on some sneering authorial whim.''<br>''[...]''<br>''Black Library can suffer more than most when it comes to terms of what’s official and what isn’t, for two reasons. Firstly, at its inception and during the first few years, it seemed unapologetically non-canon, and from my (limited) perception, it didn’t seem to try to be anything else. It was separate from the design studio, and that was that. Times have changed, but we’re lingering in the aftermath. Like hotel room stains of dubious origin, bad things can stick, and stick hard.''<br>''Secondly, like any publisher, Black Library releases work from a host of different people, each with their own perceptions and preferences. Because of the sheer amount of material released, conflicts arise between what seem like established facts. One author has a weapon firing one way, and another author describes its mechanics completely differently. Is there an official stance? No, on a lot of in-universe stuff, there’s usually not. Interpretation and imagination within the framework is the name of the game. The issue is when people consider that a flaw, not a feature. It’s supposed to be an open invitation to creative freedom, but instead it’s often disparaged as a way to hide mistakes or lore clashes.''<br>''(Don’t get me wrong, I know mistakes do occur. Having loose canon is no excuse for crappy research or poor writing, and I would never suggest otherwise.)''<br>''As a personal example, when describing the retinal/eye lens displays in Space Marine helmets, my ideas for what a soldier can see and do with his HUD are fairly divergent from most other authors’ descriptions. I can show lore to back my viewpoint up, and they can bring lore to highlight theirs. I can also wax poetic on why I think my version is better, and makes for a better touch in a story, blah blah blah. I don’t see it as a problem, but many fans loathe this kind of thing. Luckily, I’ve never had any complaints about this exact example, but I’m being nice and not naming any authors who do fall prey to that kind of feedback.''<br>''Essentially, any difference is immediately considered a deviation. Any contradiction is automatically seen as a mistake. Although I’ve been intensely fortunate with fan feedback, and my reviews are most definitely on the kinder and more favourable side of the wall, I’ve seen a few mentions where someone flat-out says I’ve got a specific detail wrong, purely because they’ve chosen to cite a variant source as canon. It’s, shall we say, “frustrating,” but I don’t blame anyone for thinking it. It’s a complicated situation.''<br>''[...]''<br>''I’ve read 40K novels that categorically violate my opinions and perceptions of how 40K works, and I have no trouble ignoring them afterwards. Similarly with some design studio sourcebooks, if I come across an idea that I find patently, uh, “in conflict” with my views (there’s some diplomacy for you), I’ll just ignore it and try not to write about it.''<br>''Interestingly, as creators in this setting, we’re under no strict obligation to reference one another, and cooperation is usually self-driven. (The exception to this is the Horus Heresy series, which is extremely well-organised, and all of us are in constant communication.) Sure, editorial prefers it when stuff ties in together, but it’s not a mandate. Everyone views the setting differently, after all.''<br>''I still have an email in my inbox from my editor, asking “Why didn’t you reference X in your novel?” I also have my reply. It says, quite simply, “Because X sucks, and so does the guy who wrote it.”'' That’s show business for you.''<br>''So, is there a consensus?''<br>''Negatory. There really isn’t. On one hand, that’s a bit of an emotional kick to the balls. I mean, everything you do will be seen as incorrect by Some Internet Guy, and they have as much right to enjoy 40K stuff as me, you, or anyone else. I don’t sit at my desk, rubbing my hands together, delighting in the fact that I might’ve annoyed Fan #3,974,910 because I said Commander Dude Guyman zigs instead of zags. I sympathise with that irritation. [...] But on the other hand, loose canon is one of the keys to why 40K has evolved into something so completely awesome.''<br>''I’m being dead serious, here. Yes, it can be considered a mark of IP laziness, and yes, I’m not blind to the fact that 20-30 years ago, a lot of 40K’s core concepts were referential half-jokes thrown around by amateur game designers, rather than the underpinnings of a more classic sci-fi setting “envisioned” by ivory tower artistes. But the loose framework has allowed three decades of fresh canon to flood in, filling in the details without necessarily feeling too constrained by what came before. Even as someone who fiercely cleaves to canon at every opportunity, I’m constantly surprised by the sheer amount of white space left open to explore and set up shop.''<br>''Within the possibility of endless interpretation lies the potential for freedom. What matters is respecting the source material, contributing to it, and sticking to the theme. And that ties right back into my first column, because no matter who’s writing the details, 40K has some unalterable themes, etched in the stoniest of stone. They’re the key. They’re what matter most.''<br>''Get the atmosphere right, and you’re halfway there.''<br>''Aaron Dembski-Bowden''<br>Source: [https://web.archive.org/web/20111127203730/https://www.boomtron.com/2011/03/grimdark-ii-loose-canon/ Boomtron: GrimDark II: Loose Canon (posted 10 March 2011)] ''(saved archive page, dated 27 November 2011, last accessed 15 April 2020)''