Hm... either I'm reading this incorrectly, or this only applies to

> a national, racial, religious group or a group defined by their ethnic origins

Can you clarify why insulting someone with "rapist" is outlawed?

If you publish it, it's libel. There's a difference between "so-and-so is an asshole" (not a fact, haha), and "so-and-so committed a crime" (a fact). Whether it's a civil or criminal matter depends on the jurisdiction. The UN is against criminalizing defamation because it limits freedom of expression.

> Can you clarify why insulting someone with "rapist" is outlawed?

In case the second link did not lead you to the correct section:

    Section 186
    Defamation
    
    Whosoever asserts or disseminates a fact related to another person
    which may defame him or negatively affect public opinion about him,
    shall, unless this fact can be proven to be true, be liable to
    imprisonment not exceeding one year or a fine and, if the offence
    was committed publicly or through the dissemination of written
    materials (section 11(3)), to imprisonment not exceeding two years
    or a fine.

OK, thanks. So free speech is limited even more than I thought :) But at least you're consistent, I'll give you that.