This is our top-level category, or looking at it another way, it is the root category.
Ideally, every other category should be a subcategory of at least one other, and every article should be in at least one category; many will fit well into two.
All pages (except for episodes and guides) should be in
[[Category:Index]] and any appropriate subcategories. "Organisation" is intended for all administrative matters and "Images" is for any images. A full list of existing categories can be found at Special:Categories.
To add a new category to a page, just add
[[Category:Categoryname]] to the end of the article or existing category page.