A. "Cross Vector" -A line that bisects both the Winding's Crossing Path of a Face and the Face edge parallel to the Crossing Path.
B. "Cross Point" -A Face vertex that is the end point of the Cross Vector with the other end point being the middle of the opposite edge.
C. "Cross Face" -One of the eighteen Faces fully crossed by a Winding. Each Cross Face has a corresponding Cross Vector and Cross Point.
D. "Terminal Face" -The one of two Faces where the Winding ends. An End Face is not fully crossed by a Winding.
E. "Terminal Edge" -The last edge crossed by the Winding's Crossing Path as it enters the End Face.
F. "Terminal Vector" -A line that connects the mid-point of a Terminal Edge with the opposing vertex ("Terminal Point" below).
G. "Terminal Point" -The opposing vertex of the Terminal Edge and one of the end points of the Terminal Vector.
H. "Cross Terminal Point" -The Cross Point of the Cross Face sharing the Terminal Edge with the End Face.
J. "Cross Terminal Vector" -A Cross Vector on a Terminal Face that ends at a Cross Terminal Point (H above).
K. "Midpoint Edge" -The icosahedron's edge that when crossed by a Winding and divides the Winding in equal size parts of nine Cross Faces and one Terminal Face each.