Layers can be dragged up and down the Layers table on the Chute Faces tabsheet, so related layers can be grouped together instead of sitting wherever the order they were created or imported in left them.
Dropping below the last row moves the layer to the end of the list. The moved layer stays selected, so you can drag it again straight away.
The order of layers is recorded by their LayerNo, so moving a layer renumbers it and the layers it moves past – this is what makes the new order stick when the project is saved and opened again. The same set of layer numbers is always reused, so no number appears or disappears; only which layer holds which number changes.
Every face moves with its own layer, so reordering never changes the drawing, the geometry, or the results of a calculation – only the order the layers are listed in.