This feels almost like SYN/ACK/NACK, but for people. Which means you could DDoS an aristocrat by sending them a lot of visiting cards.
My first thought was that this would be an interesting protocol for calling someone. I often receive more annoying robocalls on my personal phone than welcomed calls from unknown numbers. My usual solution is to quickly google the number to see if any scam reports are available and then quickly answer if not. But I might start the practice of texting ahead of calling someone unfamiliar with a quick message like “This…
Hitta.se (https://play.google.com/store/apps/details?id=se.hitta.andro...) will automatically look up the caller's name in the (equivalent of the) yellow pages.
I assume there's an equivalent in most other countries?