> 9 years ago, I shared this as an April Fools joke here on HN.

That's fun.

> It seems that life is imitating art.

You didn't even beat wikipedia to the punch. They've had a nice page about minifloats using 6-8 bit sizes as examples for about 20 years.

The 4 bit section is newer, but it actually follows IEEE rules. Your joke formats forgot there's an implied 1 bit in the fraction. And how exponents work.