Wikimedia:Categorization
Category:Main is the Main (root) Category of this wiki and should only contain other categories.
You can add a texts by language category. Add the category by hand or use [[Category:{{Text by language}}]] for pages in the translation extension.
On Special:WantedCategories is a list with non existing categories.
If you use {{#translation:}} parser function please create and categorize all subcategories correctly.