Cove/Scotia
Cove moulding, or "scotia", is a fairly simple yet elegant moulding that gives an inside corner an extra texture. It is essentially a scooped out corner that eases what can be a sharp transition between a wall and ceiling, or along the edge of a stair tread. It is often seen as a simpler version of some more ornate looking mouldings, like cornice, crown, or bed mouldings.