In making a lame joke, I thought up the IP 192.0.2.5. I seem to recall that this subnet (but I thought it was this specific IP) was the default in early Sun Unix systems. Like all the Sun3’s or whatever. And since so many people were using it as their real IP, that’s the reason they had to make this range private.

The way I remember the story is that they created this “documentation” range as an official range as an excuse to block that subnet.

Having searched on the internet a bit, I can’t find any old Internet lore that has anything to do with this. Is any part of what I remember accurate? Was it just the IETF papering over a problem created by Sun’s defaults? Was it something else?