As of May 22, the following search terms are blocked on Weibo (not including the “search for user” function).
TAM
Image from “the world besieges the fortress” campaign.
Tiananmen: Some keywords related to June 4th are forever blocked from Weibo. Others are only blocked seasonally, as the anniversary of the crackdown on the 1989 pro-democracy protests approaches. Retested keywords have been previously blocked. See our list of blocked keywords dating back to April 2011 for comparison.
tiananmen – retested
天安门: Tiananmen – retested
25周年: 25th anniversary
64+屠杀: 64+massacre – June 4th is often called “Six-Four” in Chinese.
64+开枪: 64+open fire
89+动乱: 89+unrest
（六） 四＋开枪: (six) four+open fire
装甲车＋直升机: armored car+helicopter
天an门: TianANmen
平反: redress
天下围城: the world besieges the fortress – The China Democratic Party and similar organizations are holding June 4th commemoration activities throughout the US under the name 天下围城 tiānxià wéichéng (roughly “the world besieges the fortress”), including the online campaign 全民倒共、天下围城 quánmín dǎo gòng, tiānxià wéichéng (all the people topple communism, the world besieges the fortress). Read more from Radio Free Asia [Chinese].
全民倒共 all the people topple communism
Anti-Pornography Campaign: The Xi administration is leading an effort to “clear pornographic and illegal publications” (扫黄打非) from Chinese websites.
H漫: H comics – Hentai, a type of pornographic comic book that started in Japan.
凌辱: assault [a woman] – Often returns pornographic results.
Miscellaneous:
打砸烧: beat, smash, and burn – Likely blocked in reference to the anti-Chinese riots in Vietnam.
中共政治局: Chinese Communist [Party] Politburo
南周事件: Southern Weekly incident
薄熙来＋器官: Bo Xilai+organs
All Chinese-language words are tested using simplified characters. The same terms in traditional characters occasionally return different results.
From http://chinadigitaltimes.net/2014/05/sensitive-words-tiananmen-bo-xilai/#.U4V-qygx6nE.twitter