I sympathise Tom. I'm a complete beginner and the relevance of the various radii, relation to points, etc. were not immediately obvious at the outset. For example, the R6 curve brings the point curve back to parallel. That information is there but not something I would have spotted or even thought about. Track centres are 43mm apart, again easy to deduce by subtracting the radii but not obvious with no previous experience. Everything is written down somewhere but poorly collated and the forum search engine is pretty hopeless. I agree it would be helpful to have a comprehensive online description of the track functions or perhaps an article in the magazine and, not least, a track plan publication. One thing I have found invaluable is keeping a notebook as I keep forgetting or losing information sources. The pages I've devoted to accounts are a bit sobering, however.