Here you can make new Categories, Sub Categories or Genre.
If a button is grey out the name can't be removed or Renamed!
You can Fill in a new name and press the plus button, then the name will be set in the list.
Immediately after pressing the plus you get a pop up window
This is a pre-warning, a category can not be without a sub category.
Select the new category and as you see the Sub Categories screen is empty.
Fill in a new sub category name and press the plus button.
Removing a Category or Sub Category.