Books is an in-universe category. Only those books which exist solely within the Doctor Who universe should bear this category.

Books which exist in the DWU and the real world should be categorised only under Books from the real world. It is recursive to put them both under Books and Books from the real world.

Real world books that are not referenced in-universe should not be listed here. For real world fiction and nonfiction (i.e. novelisations, novels and guidebooks), use a category under Tie-in books.