Use the top and bottom pocket areas when you need to draw top and bottom pockets.
Entrance: Top Menu - Place - 3D Shell - Top/Bottom Slot Region
The top/bottom groove area acts directly on the top or bottom layer.
Layer: Set whether it is on the top shell or the bottom shell.
Grooving Depth: The depth of the groove. Based on the top or bottom surface as the starting surface, dig down or dig up. Auto-calibration automatically sets a value based on the thickness of the shell to ensure it can dig through.