Reading these sites, I've learned a few things about other (non-U.S.) countries and their laws.
Some countries have naming laws to prevent silly parents from naming their children something cruel. When you go to register the name with the city / government clerk, they can veto the name. Like, if you wanted to name the child "Smelly Diapers" or something.
A few other countries have a list that you must choose from.
My guess is that these countries want to preserve their ethnic culture.
My second guess is that parents choose an official name, and then call the child by the "nn" they really love.
I make no judgements about these laws. I'm merely passing on information. I don't know if this is what
Andrew was thinking of, either.