I was just poking around in the Misc menu and I noticed Misc->Draw->Horizontal Construction Line (XH) and Vertical Construction Line (XV). What are they for? They appear to do exactly the same thing as Draw->Line->Horizontal Line (LH) and Vertical Line (LV). Looking in the property editor, the only difference I can see is that the Fixed Angle property is Yes for construction lines and No for normal lines, which doesn’t seem to make any meaningful difference to the appearance or behaviour of the line?