‘Lineation” is a collective term for any kind of linear structure in or on a rock. It is meant to be descriptive and non‐genetic. Lineations are striae on slickensides, fold‐axes, flow‐lines, stretching, elongate pebbles or oolites, wrinkles, streaks, intersections of planes, linear parallelism of minerals or components, or any other kind of linear structure of megascopic, microscopic, or regional dimensions.