There are two different sliders (Detail and Masking) used to create and control the masks used suppress sharpening in the lower contrast areas of an image. As a rule of thumb, use the Detail slider to suppress sharpening in landscape images, and use the Masking slider to suppress sharpening in portraits. To view a Black and White preview of the masks, Option (Mac) / Alt (Win) -drag the Detail and/or Masking slider.

I would love to see a video on this – the way you explain things is so clear and comprehensive