My guess smack is that you did not know this until you had cause to look it up, and dop some research on it. Just as necessity is the mother if invention, so it is also a motivator for learning. If you don't need to know, usually you won't know, just as you likely did not know, (of course you will say you did) until you read this persons post, and felt a need to act superior.

Another example of a bored forumite who gets their kicks by downing others, simply because they can use the google search engine, and have low self esteem. Grow up smack, and spare us all, seems the Chinese government itself doesn't know half of their own regulations, so don't be a troll eh.