Finland.

Some friends inscribed their child forty years ago, a month before the birth. It seems there was some kind of tax benefits that expired with the new year. They used the name Andrea. In Spain it's a female name, but they planned to argue that it's male in Italy and that they marked the wrong cell for the sex. In the end it was a girl, so no hassle, except her birthday is fake.

Fun fact: Andrea comes from the Greek word andrós, which means man/male. https://en.m.wikipedia.org/wiki/Andrea#Origin_of_the_name

I don't think neutral names are illegal, they are just rare. Names like Kaino, Rauni and Muisto have couple of registrations per year with quite equal distribution between genders (https://verkkopalvelu.vrk.fi/nimipalvelu/).

Nimilaki defines that a first name can only be accepted if it's "become a standard for the same gender".

https://www.finlex.fi/fi/laki/ajantasa/2017/20170946

I think that means that you wouldn't be able to give such a name in cases where it has become a standard for the other gender, meaning it would be tricky to add new neutral names. It's also quite new additition so I don't think there are any cases that have went to administrative court yet.

According to https://www.kotus.fi/kielitieto/nimisto/henkilonnimet/etu-_j... the standard for same gender is 5 people that are alive, i.e. once 5 men and 5 women have that name, it could be given to either gender. Not sure what would happen if there was a huge imbalance though (like 1000 women with the name & 10 men). At least Rauni and Kaino have been granted to both genders after the law came in effect.

What is their explanation for why they do this?

I imagine it's to protect children from the Elon Musks of the world. There's a handful of rules that concern first names in Finland that allow to reject names that are bit "out there" so to speak.

For example, there's such rejected first names as "Marihuana", "Avicii", "Kapteeni" (Captain), "Salaisuus" (Secret), "Noppa" (Dice), "Hoito Virhe" ("Medicial Malpractice" as first and last name) and "Sukka" (Sock). Guess the idea that giving a boy a girl's name can have a similar effect for the child as naming them "Sock".

> I imagine it's to protect children from the Elon Musks of the world.

Hade to look that up. He apparently named his son "X Æ A-12": https://www.bbc.com/news/world-us-canada-52557291 . Will probably create some issues with future IT-systems. I know a "Jo Å" and he have trouble registering for services from time to time.

It's actually "X AE A-XII" now since "X Æ A-12" was against California law.