What are the main elements of a simple horizontal curve?

Simple circular curve elements include: Point of Curvature (PC) - where curve begins, Point of Tangent (PT) - where curve ends, Point of Intersection (PI) - where tangents meet, Radius (R) - curve radius, Degree of Curve (D) - central angle for 100ft arc or chord, Tangent Length (T) - from PC or PT to PI, Length of Curve (L), External Distance (E) - PI to curve midpoint, Middle Ordinate (M) - midpoint offset from chord, and Deflection Angle (delta).