<groan>

While we're doing SI units, I was in a taxi in Athens the other months, when I saw a sign indicating roadworks at 100{mu}. I was still a bit groggy from the previous night's big fat wedding, so I actually thought for a moment, "Hey, they place their roadworks very accurately over here", before realising that {mu} is the first letter of metre, in Greek. But this made me think: how do Greeks tell the difference between millimetres and micrometres? Do they write them m{mu} and {mu}{mu} respectively?

Peter