Another example of squaring to the cut rather than squaring to the blade is when you want to set your bevel angle to a perfect 90 degrees.
In fact if you have any automatic bevel stops, getting the 90 degree stop to actually be perfectly 90 degrees is an essential first step.
The video shows how you can establish your perfect square setting with twice the accuracy you can measure with a steel square -- the square measures over 3" of blade -- my technique measures over 6" so we can actually see twice the error on an un-square cut.
The mention in the video of using "the same technique" referes to an explination of how to build a test piece of wood that is detailed in the previous video on getting the Miter Gauge square to the Blade.
Learning Curve 99