“…It states that a family of codelines in P G(2k − 1, 2) generates an F 4 -linear code if and only if each subset of codelines generates a vector space of even binary dimension. Among the exceptional linear quaternary codes are the hexacode [6,3,4] 4 (geometrically the hyperoval in P G (2,4), see [1], Section 17.1 and Exercise 3.7.4), the extended cyclic code [12,6,6] 4 (see [1], Section 13.4 and Exercise 17.1.10) and the dual pair of codes [17,4,12] 4 and [17, 13, 4] 4 described by the elliptic quadric in P G(3, 4) (see Section 17.3 of [1]). In the present paper we study the generalization from linear quaternary to additive codes of code parameters related to those of our exceptional linear codes.…”