When drawing models, brands appeared in some places - yellow dots, which I did not know what they meant. For a long time I could not find out what this brand indicates to the user. I also asked here, but I did not get a satisfactory answer from anyone. You won't find out about it anywhere in the reference guide or anywhere else in the manuals. I was expecting something complicated. Not. It's quite simple. These are two points on each other. Don't you believe? Try it in the attachment yellowdot.slvs which I attach here. Rotate the extrude view and look at the points through the cube and outside the cube. Try to place two points on top of each other and watch what changes. You will understand immediately.