@Sudsy , that's interesting about the irrelevance of truth to defamation claims in Japan. Learned something new! But the claimant will still need to make a case that his/her reputation was damaged. This would be very hard to do in the case of employment references, where the "defamatory" information was merely passed from one person to another, and nobody else ever heard about it. As well, if the claim made was true, the defendant could make the case that by passing along factual claims of a person's bad behavior, the public interest was served, since obviously it is in the public interest that people generally behave themselves, and that bad behavior be discouraged.
It's all theoretical though since in practice it will be nigh impossible to bring a law suit against a former employer for a bad reference. You'd have to prove that such a bad reference was made in the first place. How are you going to prove this? Nobody will tell. I have plenty of experience with this and it's just a fact that employers reveal poor behavior of former employees all the time. Some corporations may advise their employees not to do this, just to err on the side of caution, but overall I haven't seen this make much of an impact in practice.
And
@MikeH , I guess you could probably find another two countries where it's handled similar to Japan. But, in common law jurisdictions truth is an absolute and complete defense against defamation claims. This is something you can easily google. In civil law jurisdictions it depends on the country. In some, like Spain or Germany, truth is a sufficient defense. In others, like Sweden, it also depends on the intent of the allegedly defamatory claim. Was it made maliciously and merely to degrade the person's standing in public? If so, it may be punishable. In the case of employer references, no way.