Chinese people who want to know the identity of the man who will be their leader into the next decade should log on to the internet. But in a country where politics are opaque and the media is banned from reporting such state secrets as the lineup of the new Politburo Standing Committee, the clues to their identities lie in what is prohibited. In the past few days it has become impossible in China to include the names Xi Jinping or Li Keqiang in a blog.