Putting it together, maybe they're looking for an exclusive story or event from 1978 in Denmark involving Brigitte and Rikke? Maybe two Danish women? Or perhaps it's a product, like a car model (VW Lupo, but that's later)? Or a boat? Since "1978L" could be a liter measurement, maybe a product from 1978. Alternatively, maybe it's a Danish event or a historical occurrence.