>>1114271I'd just like to interject for a moment. What you're referring to as SI, is in fact, Metric/SI, or as I've recently taken to calling it, Metric plus SI. SI is not an measurement system unto itself, but rather another free component of a fully functioning Metric system made useful by the Metric measures, standards, and vital system components comprising a full measurement system as defined by the US government.
Many ruler users use a modified version of the Metric system every day, without realizing it. Through a peculiar turn of events, the version of Metric which is widely used today is often called "SI", and many of its users are not aware that it is basically the Metric system, developed by the Metric Project.
There really is a SI system, and these people are using it, but it is just a part of the system they use. SI is the standard: the measures from which the others are derived. The standard is an essential part of an measurement system, but useless by itself; it can only function in the context of a complete measurement system. SI is normally used in combination with the Metric measurement system: the whole system is basically Metric with SI added, or Metric/SI. All the so-called "SI" distributions are really distributions of Metric/SI.
