A young clerk with no knowledge of the 1989 Tiananmen Square crackdown allowed a tribute to victims slip into the classified ads page of a newspaper in southwest China, a Hong Kong daily reported on Wednesday. The tiny ad in the lower right corner of page 14 of the Chengdu Evening News on Monday night, read: "Paying tribute to the strong(-willed) mothers of June 4 victims". An investigation was launched by Chinese authorities to find out how the advertisement slipped its way past censors. Public discussion of the massacre is still taboo in Beijing and the government has rejected calls...