If it's not in canon, why write it?
I was thinking about the language of canon. That's really a terrible way of putting it, but if you're dealing with translated work, your canon ends up with the nuances of the original, and the nuances of the translation. It's impossible for a translation to perfectly show the good and the bad of an original. Some times the differences come down to pedantic little details, and some times the differences completely change the meaning of the work. Technically, you could argue that different versions of a canon show similar issues (so, say, movie canon is not book canon.)
But when you say my canon, there's often a value judgment when it comes to sources with multiple versions. You have the famous "subs are better than dubs" kind of thing. Or the "the Genesis version is better than the SNES version" for example. Or the classic "book is better than movie" or the "first season is better than all the rest." As explained in that LiveJournal entry, I tend to take canon very lightly, preferring to favor anything that shows a good story versus finding the one true interpretation. However, when it comes to multiple canons, I tend to find myself being a little more strict.
Let's try an example. In the Chrono Trigger series, there's three games. The first is Chrono Trigger, followed by Radical Dreamers, and lastly there's Chrono Cross. Radical Dreamers is a sort of choose your own adventure and a side story. In my 'canon,' Chrono Trigger exists, and Radical Dreamers exists if it's got something fun in the plot. Chrono Cross is semi-infamous for saying that your actions in Chrono Trigger were ultimately futile, and your characters from the first game are more than likely dead. (Confirmed for three, since you talk to two ghosts and kill the third. Some people argue that Lucca escaped from the burning orphanage past the soldiers.) I categorically see no benefit in having the canon say that everything you did was futile. Particularly if it was for a seemingly stupid reason.
Let's try another example. Wild ARMs 2 has a character that seems to be gay in the English translation, and another that it poorly tries to hide as being gay (as in, he gets called 'she' as soon as he mentions that he's in love with his lover.) Depending on the fanboy, the Japanese version has the former as ambiguous, and the latter as gay. I prefer to read them both as gay, since awkward gender changing is homophobic stupidity and the guy as being gay is an interesting plot point.
Let's try another example. Satsu, a friend of mine, was translating Eien no Filena. I played the game in Japanese, and picked on pretty quickly that the crossdressed heroine had a woman who seemed to be like a wife to her. Since this woman goes through the entire game as your heroine's wife, and you end the game with them running off together, I guessed there was lesbian overtones. This was my canon. The translation supported it, making my canon also canonical in the translation.
Let's try another example. Valis is a series that was made as sort of a magical schoolgirl drama. The plot of almost all the games is that being filled with love and friendship would let you conquer anything. Your heroine, Yuko, has a best friend, Reiko, who even beyond death protects her. The final game in the series is a shameless porn game. It's not my canon. The game where Yuko sacrifices to live in heaven forever is also not my canon, because it seems like a rather anticlimactic way of ending her role in the series. Also, the sacrifice involves the annoying stereotype of better armor involving less clothing.
As a final example, let's look at Idea no Hi. It's an obscure and quirky SNES rpg. It's untranslated. All I know of it is babelfished and by my rather poor Japanese reading skills. Still, my 'canon' of the series is something I feel pretty confident in. Yeah, I may not know exactly what someone is saying, but I can pick up enough to tell that, say, one of the evil generals burned the laboratory of Poe's son, who possesses your medium as a ghost. In a climatic scene, Poe confronts your party in a prison, and the ghost appears, saying something like, "That Demoku, that damned man - he killed me." On the other hand, I'm pretty sure your hero's supposed to be a pervy snide little teenager, and that he ends up having a kid at 13 with your heroine (fifteen at the max, if you are generous with your timing of the game.) That's - not in my canon. Neither is the racist iconography of parts of the game. I'm sure if the game was translated, the racist iconography would've been changed heavily, and the perversion and the underaged aspects would be changed.
So, is there a pattern to all this? I suppose you could sum it up like this -
If the ambiguous canon has a plausible answer, use it.
If the ambiguous canon's canonical answer is boring, don't.
If the ambiguous canon clarifies the canon in an annoying way, the two versions are contested canons.
If the contested canon doesn't make a good story, it's irrelevant.
If the contested canon has a 'better' version, that version is canon.
If the contested canon is problematic, pick the less problematic version.
So, what do you think? I suspect if someone has a stricter version of canon, the ambiguity would be frustrating. I used mostly game canons because they're handily translated and they're easier to compare than say, movie and book canons.