In South Africa we've got several traditions on the go at the same time, so to my knowledge there isn't a rule about naming ... though now that we've got a remarkably democratic (sometimes nannying) Constitution, it might well be possible to challenge a name in court on human rights grounds.
For example: in the bad old days, many Afrikaners supported Nazi Germany, sometimes from conviction, sometimes because England was their ancestral enemy. And one family that I know of named their son (born in the early 40s I suspect) Izan. Nice and subtle - Nazi spelt backwards. Why they wanted a backward Nazi for a son, I'll never know ... the only reason I'm aware of this case is that the naming father became a Cabinet minister (Foreign Affairs), so the family were in the public eye. I would expect that parents trying to register that name or a more modern version (maybe Pol Pot?) might be challenged by the person at the registration desk.
However, then you get black African parents, with their traditions that sound strange to others sometimes. You're Dutch, right? Well, how about naming a baby Oupa? Or Ouma? Happens regularly! And I suppose it makes some sense - rather than use the grandparent's name, you use the word.
There is also a strong tradition of nonce names and omen names: if you win something close to the time of your child's birth, you can name him Lucky. Or her. Or you select a virtue or a quality that you hope the child will embody, like Prudence or Grace, but also like Knowledge, Doctor, or Wiseman.
This would be a challenge to legislators ... to my knowledge they've ducked it so far.