What is the function of this?

[[Cl...]]

In the strategy of a 2d curve is this Chord height option. What is its function?

[[Da...]]

F1 Help says:
Defines the distribution of the curve points over the entered chord height. Each point is calculated as the intersection with the chord height equal to the entered value. Therefore, the straighter a curve section is, the less points are measured.

[[Cl...]]

Thanks. I'm looking for a way to use PCM to make a curve expand as the part family grows.