Regarding the phrase it likely refers to one of the following contexts depending on your specific project:

: A common valid private IP might look like 192.168.1.161 .

. It allows a character to "trace an IP" or "hack a server" without inadvertently pointing the audience toward a real-world server owned by a private citizen or a corporation. It is a safety mechanism that preserves the "suspension of disbelief" for the layperson while signaling a wink to the technically literate that the world on screen is purely fictional. The Symbolism of the Non-Existent

Because no octet in an IPv4 address can exceed 255, 264.68.111.161 is invalid .