I think the original expectation was you wouldn't segment it, and that's why each address class has it's own defined range of ipv4 space. See rfc870, MITs /8

I think the original expectation was you wouldn't segment it, and that's why each address class has it's own defined range of ipv4 space. See rfc870, MITs /8 was listed as "temporary" (lol) and they had several separate specific class Bs. The ghost of /etc/networks rattles in the distance..