Ordinarily, when you leave off selecting a taxonomy term from a filter that says "Is one of", nodes tagged with that term will not show up in the View. However, when you make that filter an Exposed filter, the behavior changes. Even if you checkmark "Limit list to selected items", nodes tagged with that term will show in the initial view. Users see this item, but if they filter, they won't see it any more. Not exactly intuitive.
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