Can the wise people of HUKD help me unravel a mystery that has bothered me of late:- What are Fog lamps on a car??? . and what are they used for? ? . I thought I knew, I thought there was a clue in the title. I thought that they were for when it was foggy!!! Obviously I am wrong with the number of vehicles that have them on irrespective of visibility or weather conditions. Has the Highway Code been updated without informing me?