Better read as: Sticking to Canon Questions.
Suppose that an anime has a manga correspondent to it too, and the anime has a fair amount of filler that builds up season after season. Some fans of the manga whom also watch the anime may not wish to be bothered with all of the filler, and wish to ask for which specific arcs/episodes cover only canonical events with respect to the manga.
A very simple example: Naruto. There's lots of filler, even with the second series in it. Someone that's a fan of the show, but doesn't want to get bogged down by the filler, may want to only watch the episodes that progress the storyline.
Should these sorts of questions be allowed, and if so, under what pretense?
I don't have an objection to allowing these sorts of questions, since it's something that comes up with most long running series. If we do start allowing them, however, we would need to define what kinds of principles we allow those questions under. I'm thinking that something like, 'Man this filler really sucks, what's the next arc' questions wouldn't be constructive (and I could be proven wrong!).
EDIT: To add to the discussion, an idea being bounced around would involve well-defining canon to allow these questions to be answered. In my mind, the problem is "well-defining" the canon of a series, since some series are anime-only, incomplete in manga, or a mix of both. Perhaps limiting the scope of these questions to long-running series, with a well-established canon, would help in giving these questions more relevance and less subjectivity.
To the "maintainability" point - I feel that the Community Wiki functionality would be very ideal for this; it allows for flexible maintenance of the list of non-canonical episodes, and everyone can participate.