I agree, Silverboy is Silverboy. I don't think he claims to be a top linguist and you would certainly have to be one of those to take on another posting identity and not leave any fingerprints/linguistic markers, from another identity, and there doesn't seem to be any connection between John and SB that you can make out from their writings. I'm not saying that John or SB are not linguists but I am saying they are not topmost linguists enough to get away with it over a period of time and posts. These things can get misleading though. Just because one writer says 'Have a good one, comma, Bill, it doesn't mean that he is one and the same person as another poster who writes the same thing.

I've just been told I need to bring a full medical certificate to China with me. But I am a bit hesitant as the quote I have been given is hundreds of pounds, not able to get such a comprehensive one on NHS. Is this normal?