The angels that appear on the cover follow the structure described in the texts of the Medieval Christian Gnostic Tradition, where there are 72 guardian angels divided into nine choirs of eight angels each.
Each letter indicates, along with the number, the Hebrew name for the Angel, the planetary formation to which it belongs, the ruling planet, the key word that summarizes the task, the area of interest (emotions, health, work, fortune ... .) and divinatory importance.