Abstract. Quaternary Z RM (r,m) codes were defined to study the Z4-linearity of ReedMuller codes. In the literature two different definitions of such codes can be found, denoted Z RM (r,m) and Z RM (r,m). We will show that both definitions are equivalent exactly for those values of r such that their binary images are Reed-Muller codes. We will compute the rank and the kernel of their binary image. Keywords. Reed-Muller codes, quaternary codes, rank, kernel