When is a landing required for an exterior door?

There shall be a floor or landing on each side of each exterior door. Exception: Where a stairway of two or fewer risers is located on the exterior side of a door, other than the required exit door, a landing is not required for the exterior side of the door. The floor or landing at a door shall not be more than 1 1/2 inches (38 mm) lower than that top of the threshold. Exception: Provided that the exterior doorway is not for the exit door required by Section R311, the step between the landing at an exterior doorway and the top of the threshold shall have a rise not greater than permitted in Section R314.2. The door, other than an exterior storm or screen door, shall not swing over the landing.