What I'm confused about is how the characters get the "D" initial in their name.
Everyone else in OP universe is stunned when they hear that someone has the "D" in their name. It's not just about writing it into someone's birth certificate?
I mean how do they know when someone have it or not, because it was revealed that they know if the "D" is there since birth. Ace's mother named him Gol D. Ace and I don't think someone can give this "D" so easily when the rest of the world if making such a big fuss about this.