What is SGND pin on nzxt c series c1500 platinum

Hi,

The manual of nzxt c series c1500 platinum shows two SGND pins on the PSU side (one in the 18 pin connector and one in the 10 pin connector). What are they? How do they differ from the regular GND pins?

They are not for sensing cables, as there is a separate GNDs pin for a sensing cable on GND.

Can anyone explain SGND?