Hi, Bill:

1) Thanks for the reference. However, Informative Reference 7 of our IETF Draft cites another IANA document which puts the initial date of the 240/4 topic back to 1981-09 which was much earlier, in fact, coincided with that of RFC 791.

2) My curiosity questions were not about "when" or "how", but "why" and for "whom". Particularly at a time that IPv4 was planned to be "dead" soon, what was its "Future" that deserved to be Reserved for?

Regards,

Abe (2022-03-11 09:36)

On 2022-03-10 23:16, William Herrin wrote:

On Thu, Mar 10, 2022 at 7:51 PM Abraham Y. Chen <aychen@avinta.com> wrote:

1)    " ...  should be ...  ":    Instead of "hand wave", this is a diplomatic expression to challenge the software engineers' knowledge of the networking program code for the current case. Ever since we started our study, we were quite puzzled by why the 240/4 netblock was regarded so special? Why no one could tell us what led to its current status, and even after IPv4 was set to transition to IPv6?

https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml

Which leads to RFC 1112 section 4, the disposition of which last
changed in 1989.

You are now informed about its current status along with when and how
it got to be that way.

Regards,
Bill Herrin

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