I started out thinking this might be about the 'dark' web and private name servers, but then I started to laugh - thanks!

For those unaware of the dark web, it's not a spooky, menacing thing. It's just all those servers with IPs that are not in the global name service (DNS). You either know the IP, have the lookup in your local 'hosts' file, or it's in your local-network name server. No magic involved. Old guys (like me!) might tell you that ther was a time when everyone needed to just know the IP.