Often-Overlooked TANDEM Drawer Adjustment

If I have a drawer cutout that is 23.5” deep and i want to put a drawer only 18.75 total depth, what slide would I choose? Does slide get drilled into back wall of cabinet or back edge of drawer?

No sirve

The slides I ordered only have this adjustment on one side.

Would be helpful to see the side view before and after the adjustment, to see what is actually changing. I've used this adjustment on my slides and haven't noticed much of a difference.

Thanks for the tip!