Source material, as has been noted in other news files, available to be read, disseminated, and so forth throughout the Multiverse. However, something very important should be noted. It is very rarely 100% accurate. Very. Rarely. And there are usually hundreds of different permutations of that source material available. Most people outside of the two main factions will have a very hard time getting much of it at all, due to the vast amount of sheer DATA there is.
In the factions is a bit different - much of it has been collected and some of it is studied. Know thy enemy, and all. However, at best it's used as a starting point. Anyone who uses it as an absolute will almost certainly pay for it somehow. People - prominent and powerful people - are known to have died or worse for following the comic or the book they found too rigidly and bit off more than they can chew.
TRUE canon - stuff you can get IRL - is obviously the most dangerous, because most people are going to be going off of that to some extent. This is, however, the most difficult to get ahold of. Approximately 99% of True Canon is located in the Center of the Multiverse - the amorphous region at the middle of the Unified world where the entire Unification started, that used to be the original Earth the Founders came from. The Center of the Multiverse has been severely damaged in space-time and is nearly impenetrable to any character who is not a PC. Even PCs have a very difficult time, and usually require the help of one or more Founders, who have a slightly easier time penetrating the distortions.
Once within the Center, it is very difficult to find information unless you truly need it. There almost seems to be a cloaking effect about the place - you could look at a book and not realize it's what you need unless you REALLY need it. Furthermore, the journey is extremely perilous - many have entered and never returned, though many more have entered, gotten lost, and essentially were spit back out.
Most true canon that IS known is locked up by the Confederate and Union councils and is kept under lock and key. Using true canon is a TP-only activity in general.
Individual canons - source material from other universes - can be partially correct for various characters. However, it behooves you to ASK THE CHARACTER AND CAST IN QUESTION OOCLY before you do anything other than the most basic of information. Go on the assumption that you may be ICly wrong, and you may DIE for that mistake.
Occasional comedic effects and occasional real IC usage are alright. But don't tromp on other people's toes with this, and don't break the fourth wall rampantly.