> may be based on the assumption that the source is an incandescent filament. That stopped being true in the late 90's/early 2000's when HID headlights entered

> may be based on the assumption that the source is an incandescent filament. That stopped being true in the late 90's/early 2000's when HID headlights entered the market, and the standard was further updated a few years ago (after a decade's delay) to allow for adaptive-shape headlights (ie ones that can control the shape of the high beam, for example to still provide high beams, but not in areas occupied by oncoming traffic.)