References to the 1989 army crackdown on student demonstrators in Tiananmen Square are taboo in China. If mentioned at all, the protests are described as a “counter-revolutionary rebellion”.

However, one young Chinese man has now posed boldly on a blog hosted by one of China’s biggest servers wearing a T-shirt emblazoned with the date – June 4 – but in a code that may take time for censors to spot.

His T-shirt reads VIIIIXVIIV. The photos are accompanied by a hint that reads: “Here’s a clue – these are four numbers.” Whoever posted the photos of the T-shirt yesterday was well aware of the risks involved. That person placed a brief posting above the photos, reading: “This year this kind of T-shirt is very much in fashion. The design is very beautiful (those who don’t understand should do some careful thinking, those who understand shouldn’t say a word)."

Several readers have posted comments. One reads: “This is too easy. VIII (8) IX (9) VI (6) IV (4). Do I get a prize?” Another says: “Where can I buy these?”

Chinese refer to the day when the People’s Liberation Army swept into Beijing to end weeks of demonstrations led by students encamped in Tiananmen Square with the loss of hundreds of lives simply as “6/4” or June 4.

Each year as the anniversary draws near, the authorities step up security across the country. Many of those who took part and who remain in China are rounded up and detained for several days or weeks. Others find themselves under virtual house arrest. Checks on internet chatrooms, blogs and comments are even more rigorous than usual.

This year, however, the security is likely to be doubly intense. The twentieth anniversary of the crackdown falls in June and the authorities are eager to avoid any instability just months before the Communist Party marks on October 1 the sixtieth anniversary of its takeover of power in China.

A huge military parade will pass in front of government leaders in Tiananmen Square, where Chairman Mao declared the People’s Republic six decades ago.

Any attempt to use the characters 6-4 as search key words on the internet in China run into an immediate block, crashing search engines for several minutes. But for how long will the date written in Roman numerals escape the attentions of China’s cyberspace police?

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