In spite of frequent observations, and of sonic important consequences for industrial applications, the glide motion of dislocations in non-octahedral planes of fcc metals and alloys remains rather poorly known, and not sufficiently considered for the analysis of mechanical properties. Following the pioneering work of C. Crussard in 1945, the results of several independent studies are compared and shown to be fairly consistent. They indicate that non-octahedral slip occurs under fairly well known conditions, and that it can be described by a kink-pair mechanism acting on screw dislocations dissociated in intersecting {111} planes. It has a drastic effect on the intermediate-temperature mechanical properties of fcc crystals and aluminum-based alloys, as well as oil texture formation under conditions of severe plastic deformation.