J. F. Magloughlin comments: I would like to compliment Woodcock & Mort on an important attempt to bring more order to the complex and under-attended world of fault rock classification. The authors aptly point out several of the persistent difficulties in fault rock terminology, such as the original cohesive-versus-incohesive dichotomy in Sibson's (1977) classification, and they appropriately attempt to create a more nongenetic classification scheme.