I bet they used Domain Connect[1]! That's the mainstream cross-service domain management protocol, but they require each service explicitly register with each

I bet they used Domain Connect[1]! That's the mainstream cross-service domain management protocol, but they require each service explicitly register with each domain registrar. I also don't think any of the companies involved are super invested in it right now which is a shame. [1]: https://www.domainconnect.org/ https://www.domainconnect.org/