The Time-Space Visualiser category is the highest-level category for articles written from an in-universe perspective. Like its namesake, our TSV lets you look at anything, anywhere in the universe. But remember, the TSV only sees into the past. That's why all articles in this category should be written in the past tense.
This super-category should have only one individual article attached to it: the one which describes the Doctor Who universe itself. Otherwise, it should remain a "category of categories".
Within this super-category, you will find reference to things which exist in the real world, but are a part of the Doctor Who universe itself. Perhaps they are planets, like Mars and Earth. Maybe they're people, like Agatha Christie and Elizabeth I. Or possibly they're scientific concepts, like evolution. These are placed within categories that follow a strict naming convention, so as not to confuse them with similar categories within Category:Real world.
Things which exist in the real world, but have been referenced within the Doctor Who universe, are in categories with the syntax: <noun> from the real world. Thus, category:People from the real world is a category here in Time-Space Visualiser. But category:Real world people is the category for people who exist only in the real world.
This category has the following 18 subcategories, out of 18 total.