I hadn't heard of a "nonillion" before, so I looked it up[0].

  often attributive
  US : a number equal to 1 followed by 30 zeros
    -> see Table of Numbers
  also, British : a number equal to 1 followed by 54 zeros
    -> see Table of Numbers

Hopefully that clears things up. /s

[0] https://www.merriam-webster.com/dictionary/nonillion

The IANA is using the first 3 bits of IPv6 to divide up the space.

The ones currently in use are

- 000: "unspecified/loopback/embedded IPv4."

- 001: global unicast (GUA)

- 111: LLA/ULA/multicast

So IPv6 addresses starting with 44 (44::/16 or 0044:0000:0000:0000:0000:0000:0000:0000/16) would fall into the 000 bucket above.

There's already carve-outs in 000 (::1 and the embedded IPv4 stuff).

Why not?