Non-Canon

''So... a mortar?''

Any creator-made information that doesn't count towards the core facts in a franchise's universe is considered non-canon. This could be an event in the future, a dream, or a story one person is telling another. An event or character that is separate from the canon is also non-canonical. With non-canon, the creators could get away with showing something that is impossible or doesn't actually happen as it doesn't affect the overarching lore. This gives them great creative flexibility as any and all situations that happen to the cast are canonically ignored. If an event is feasible in terms of physical possibility and fitting the cast's personalities but is never mentioned, it could count towards Non-Canon.

What counts towards being canon and not could be confusing in episodic TV shows. Characters do not reflect on past episodes other than in Two-Parters, Self-Referencing moments, for Nostalgic Catering, or to make a quick joke.