This is not exactly what is meant. The issue is if you open a file that is just a promoter, you just see a bare backbone. The suggestion is to instead show the part without the backbone. To see an example, add a part to the canvas, then use the focus in option to go inside the part. Inside you see a bare backbone. This a bit confusing to people. The solution perhaps is not to show the part without the backbone but put a glyph of the role of the part in the corner of the screen perhaps. We can discuss.