Used to group only categories.
This Super-Category groups together the themed categories of cards, like Summer or Xmas.
These categories (such as "Theme:Christmas" or "Theme:Summer") are automatically created and added if you use the template here.
FYI, how to use template: when editing, click the green puzzle icon, and search for "sidian info". When the template is added, you can input details like victory comment, voice actor, and theme.