If that was supposed to be the case it's been fucked up since they first gave 19...

vel0city 5 months ago | parent | context | favorite | on: Airlines are running out of 4-digit flight numbers

If that was supposed to be the case it's been fucked up since they first gave 19.0.0.0/8 to a car company in 1988, or when IPv4 was originally designed with such a small address range.