Actually, they are really parking lights. Most Euro Countries stipulated that if you left your car in the road overnight, you must have a front & back light on (ones nearest the centre of the road). Euro 02s were designed for this, by having the little bulb in the headlight and the extra wiring from the indicator switch (US cars, at least my '76s, do not have this feature).
If you leave the indicator to the left & switch off the ignition, front "parking" light & rear taillight will come on & vice versa if your indicate to the right.
Of course, if you were driving in a French City, you had to turn your yellow headlights off, and just run the "parking/city" lights. Typical of the French to be different!