Censorship, enlighten us

I was just reading Jessie's blog about her film release and she said that the version in Singapore was censored, while the international wasn't.

Now here comes the question that I have, what is exactly censored in Singapore? And why is that?

And is there a censurship in HK, or the rest of China?

For instance in Belgium there is only one kind of censurship: we cannot diss the royal family, which I find it pretty stupid since they are just a bunch of retards living through or taxes!

But appart from that we don't have any censorship, take the US, same shit, thank you first amendment.

But what about the rest!

Let's start up the discussing and don't hesitate to enlighten me!