I'm just thinking about my wife's home town of Carrara, Italy. When we lived in Como I was based in Milan for work and was asked how much Italian I knew. I told them it was mainly swearing and warned them it was a bit fruity. Not to worry, they said. After gustily reeling off a litany of unimaginably rude epithets I was met by a rather awkward silence. I then informed them that apparently Carrara was a rather rude place (which they had probably figured out at this point).
What's interesting me now is the fact Carrara has been a manual labour mining town for millennia. I'm guessing this uninterrupted working class vein is possibly unique and would love to know if any other towns have a similar pedigree and accompanying shocking vernacular for other, more genteel, people. Liverpool is similar with the dockers but has nowhere near the same continuity over such a long period of time. Anyway, just musing.

