In their list of the characteristics of the biblical majuscule script, G. Cavallo and H. Maehler draw attention to both the formation and the shape of letters. They note that in the phase of greatest formal perfection of biblical majuscule: (1) there is a preference for geometric forms; most letters can be fitted into squares; (2) there is a contrast in thickness between compact vertical strokes, thin horizontal and ascending strokes, and descending diagonals of medium thickness; (3) there is an absence of decorative crowning dashes or ornamental hooks; and (4) as for the shapes of the letters, as a general rule they repeat forms and basic structures of the alphabet of classical Greece; the forms of rho and upsilon are characteristic; both have long verticals that descend below the baseline. See Cavallo and Maehler, Greek Bookhands, p. 34; see also Cavallo, Richerche sulla maiuscola biblica, vol. 1, pp. 4–12.