In the 90s domain registration was all handled through email. You emailed from an approved address, with a specific format, to change anything about the registr

In the 90s domain registration was all handled through email. You emailed from an approved address, with a specific format, to change anything about the registration. This included where your name servers were. Made self-hosting interesting when your home IP changed, or you moved, and that was where you hosted your DNS and email.