Originally Posted by Gabe15

Only wild species have official names. For all of the edible types, there is no entity that defines what is "correct", they are not published and documented like wild plants are. Since many of the same varieties grow in many parts of the world with different languages, there are many different names for each variety. The best way to keep track of the edible cultivars is to keep lists of synonyms and descriptors, which is precisely what Bioversity Intl.'s MGIS database is working on. And as for ornamental varieties (that are not pure wild species), they will most likely never have that kind of work done with them because edible bananas take the research priority.

So the answer the question directly, for edible banana names, nothing makes them official. There are just those that are more widely used and associated with specific varieties in different regions.