With this command you can purge unreferenced layer definitions. Unreferenced layer definitions are not used as System layer nor as a layer for Material properties.

All unreferenced layers are displayed in the left section of the dialog box. You can mark one or more layers with the mouse and delete them by clicking the button Remove. The button Remove all deletes all (also those not marked) layers from the list. The changes only become effective when you click the button Save. With Cancel, the changes are discarded.

Further information about layers and layer assignments can be found in the sections Layer and Material.