Tiananmen Square 1989 death toll was at least 10,000 according to UK documents

This bit confused me:

> China bans all activists' commemorations and highly regulates online discussion of the incident, including censoring criticism. But it is marked annually by activists elsewhere in the world, particularly in Hong Kong and Taiwan. [Emphasis added.]

Hong Kong is part of China, albeit as a special administrative region. So does the ban not apply in HK? Or does it apply in theory, but in practice is not enforced? Or are HK-based activists just more willing to flout the ban?

Hong Kong is not China under the two systems policy, hence why flights between the mainland and HK are considered international. Until recently, the laws were completely separate with the communists basically not interfering with legal aspects of HK society. Then they started abducting booksellers and prosecuting human rights activists, it’s safe to say that the two system policy is winding down quickly.

> Hong Kong is not China under the two systems policy

Isn't the full name of that policy "one country, two systems"?