Attached Link: http://www.renderosity.com/index.ez?viewStory=12939

I'm confused. (Not a rare occurrence..) According to this tutorial on P6 lights, some of them need to be rotated by -360 degrees. Why?? When I was at school, there were 360 degrees in a circle. So rotating by -360 degrees would take the light back to the starting point. Has someone changed that? Or am I missing something fundamental? ... See attached pic or click on the link to view the article.. Confused (as ever) Cheers, Diolma