The repression of '89, however, remains entirely taboo. You will virtually never see a direct reference to it in the Chinese media or in any kind of public forum. The closest thing I have seen is oblique references to the "political disturbances of the late eighties" buried within articles on recent Chinese history.
There has been one exception to the rule: in 2009, on the day of the Tiananmen incident's 20th anniversary, the English edition of the Global Times amazingly ran a front page story on the legacy of the event. Although the article correctly described how sensitive the topic is in Mainland China, and how it is never openly discussed, it then went on to toe the party line, stating that the government was correct in putting down the protests, and that this decision has given China twenty years of growth and prosperity. Perhaps unsurprisingly, this article no longer appears on the newspaper's website. Even so it is amazing that it was published at all, and I am sure that it would never have got past the censors had it been written in Chinese.
It is untrue, as it is sometimes claimed, that most younger Chinese have no idea what happened in 1989. In fact a basic knowledge of the events seems to be pretty widespread, at least amongst people with a decent education. If you just mention the 六四事件, or the "six-four incident" as it is known in Chinese, most people will know what you are talking about. What is true is that most Chinese, at least those too young to remember that time, have probably never seen photos or videos of the demonstrations and of the subsequent bloodshed. The famous photo of the man with his arms stretched out in front of a tank is not at all well known within Mainland China.