Motor-vehicle drivers may give the luminous warnings specified in Article 33, paragraph 5, of this Convention, instead of audible warnings, between nightfall and dawn. They may also do so in daylight hours for the purpose indicated in paragraph 1(b) of this Article, if to do so is more appropriate in the prevailing circumstances.
This requirement shall not apply, however, to main-beam or dipped-beam headlamps when their luminous warnings consist of the intermittent lighting up at short intervals of the main-beam headlamps or the intermittent lighting up at short intervals of the dipped-beam headlamps or the alternate lighting up at short intervals of the main-beam and dipped beam headlamps.
