No Idea of how the different points got their name, however a friend in Germany told me that the 'Spike' point that pups was kind enough to show was only manufactured for the American Market.

I would also say that the Square Point is only slightly different from the Spike point as there is a slight radius instead of two angles meeting at a 90 deg which results in a nice little bit to bite you when you momentarily lose your concentration. Yes I speak from experience.