Circulando con lluvia muy intensa, ¿se tendrá que usar obligatoriamente el alumbrado antiniebla posterior?

When driving in very heavy rain, heavy snowfall, dense clouds of dust or smoke, or thick fog, we must use the rear fog light. FRONT FOG LIGHT: - Fitting and using it is NOT compulsory. - It is white or selective yellow. - It may be used, if you choose, in fog, heavy rain, snowfall, clouds of smoke or dust, or in similar conditions. - It may also be used on narrow roads with many bends, that is, roads with a carriageway 6.5 m wide or less that are marked with 'dangerous bends' signs. REAR FOG LIGHT: - Fitting and using it is compulsory. - It is red. - It must be used in THICK fog, VERY heavy rain, HEAVY snowfall or DENSE clouds of smoke or dust. During the day, the front fog light may be on with just the position lights, but it can also be used together with dipped headlights or main beam. At night, it must be used at least with dipped headlights. During the day, the rear fog light must be used at least together with the front fog light or dipped headlights. At night, at least with dipped headlights.