الخفي والمشكل والمجمل والمتشابه
Khafi, mushkal, mujmal and mutashabih.
These are the four types in which meaning is concealed. The book places them opposite the manifest categories. As the footnote explains, khafi corresponds to zahir, mushkal to nass, mujmal to mufassar, and mutashabih to muhkam.
Only the names and their opposition are needed now. Their technical definitions and rulings belong to the next lesson. The contrast prevents us from treating every case of obscurity as the same kind of problem.