Currently there are a multitude of tags for questions about alternative movie versions. First of all, the tags versions and alternate-version, which have largely the same tag descriptions and usages (some questions even use both tags). Then there are the less frequently used movie-edition and directors-cut (which is more specialized, but could easily be covered by a broader tag).
Since the current situation is overly confusing, how to proceed with those tags?
EDIT: Since the appraoch proposed in NapoleonWilson's answer has been unanimously accepted by the community, I'd hereby ask the moderators to make directors-cut, versions and movie-edition synonyms of alternate-version and tag this question as status-completed when done.