Think he's meaning for the depth settings so the depth settings match up with the scale.
Its mentioned in the manual but basically all you need to do is put the saw on the guiderail, set the scale to the zero point then adjust the screw on the scale when the blade is down so the teeth just touch the work piece under the rail.
That sets it so when you use the depth settings they work out right as the cutting diameter is very slightly altered when the teeth are sharpened.