Domainal trace lineation is defined by the intersection of two foliations, where at least one of these foliations is a composition banding formed by deformational processes (e.g. differentiated crenulation cleavage). The diagnostic feature of this lineation is a pronounced striping observed on the foliation surface that intersects the banding. An example of domainal trace lineation is displayed on the dominant foliation surfaces in New Harbour Group metasediments, near Rhoscolyn, Anglesey. The lineation is produced by the intersection of two foliations of domainal type, which produces prismatic domains resembling stretched objects. This probably explains the previous identifications of the lineation as a stretching lineation. The new interpretation of the lineation has potentially important implications for the deformation history of the New Harbour Group.