Another interesting function of xschem is the 'Propagate highlight': some devices (typically voltage sources, ammeter devics, resistors , diodes) can be configured to propagate a net highlight from one pin to the other. This is very useful to visually inspect your circuit, you highlight a node (for example a high voltage supply) and you want to see where this HV voltage goes throughout your circuit. You need to configure some selected devices to propagate this information, as explained in the video.