https://www.theregister.com/2024/01/29/icann_internal_tld/ [theregister.com]
The Internet Corporation for Assigned Names and Numbers (ICANN) has proposed creating a new top-level domain (TLD) and never allowing it to be delegated in the global domain name system (DNS) root.
The proposed TLD is .INTERNAL and, as the name implies, it's intended for internal use only. The idea is that .INTERNAL could take on the same role as the 192.168.x.x IPv4 bloc – available for internal use but never plumbed into DNS or other infrastructure that would enable it to be accessed from the open internet.