I hadn't realize that I have to ask your permission to ask other people what languages they may or may not speak. You want to point out the forum rule that says it's bad form to make remarks about other members' possible background?
It is nosy/impolite at best and offensive at the worst when you involve someone's nationality in your discussion of something completely irrelevant of nationality. It implies stereotyping. Where he comes from and which dialect of Chinese he speaks have nothing to do with his information on the name of the WZ-10 team. His way of spelling the Chinese words in alphabet may be different from yours, but it does not mean his way is wrong. Keep drilling on his spelling is disrespectful. And making a connection with his nationality and his native language is even worse.
It is a common courtesy NOT to ask someone about his/her background, especially on an internet forum. Ever heard of respect for privacy?
BTW, the forum rule says not to make comments about someone's English. So by the same token, do not question someone's Chinese.
