I think we need a tag for questions about differences between anime/manga versions and even TV series/movie versions. That way it's easy to sort all of these questions without attempting to search for them. And it would be easier to implement this now rather than once we have even more questions.
I don't really know what to call it though.
Edit: To clarify, I think there should be one tag for all types of version comparisons. I don't want a tag for each type of comparison. Please speak up if you disagree though.