I was under the impression that it came from the government to the event organisers (who we were contracted by), but it's possible it was a list compiled by them based on their experiences (they were a South Korean company who had done a couple of Chinese events before).

The list itself was really short, it was more interesting for the fact that our video game streams would be watched closely and that we would get kicked out of the country, than for it's content.

We called it "the Ts", off the top of my head the banned words/topics were Taiwan (call it "Chinese Taipei"), Tiananmen, Tibet.. and there were two others, both (I think) beginning with the letter T.