Indispensable for Hierarchical Categories

Don’t understand why this plug-in doesn’t have more reviews. It’s one of the first I install. I have sites with a subject category and then a subject-date category. this allows me to keep the dates with the categories without naming them with both the category and the date. Otherwise, I would see 1978 chosen but not be able to check that I had chosen photos>1978 or notes>1978. Repeating the category name with every date would add twice the number of terms in far too many places.