For a single straight flight from one level to the next.
For two or more straight flights intersecting at an angle other than 90 degrees.
For two straight flights intersecting at a 90 degree angle.
Two straight flights turning back 180 degrees, sharing a common center support wall.
Two or three straight flights turning back 180 degrees with one or two landings and an open center well.
Stairs where inside and outside stringers are arc segments of two concentric circles in plan.
Stairs with one or two straight flights combined with a circular flight.
Stairs where either the inside stringer, outside stringer, or walkline is a segment of an ellipse in plan, with the remaining two being offset forming ovals.
Stairs winding around a center support.