An interesting TUHS thread from 2022 about the origins of the BSD license:
https://www.tuhs.org/mailman3/hyperkitty/list/tuhs@tuhs.org/thread/G354W5YHSHXY2NZ4BYJEKQECTUMK7X7I/#7EWKS5KWJAS7YWQ7AVXDME4Y5XGBXXM2

On Sat, Oct 12, 2024 at 11:47 PM <arnold@skeeve.com> wrote:
Hi All.

I'm working on revising my book on basic *nix programming, and for
the new chapter on sockets, I want to include some code from 4.2 BSD.

Is there a copyright file somewhere for that code?  I'm sure it's
copyright the Regents of the University of California, but I'd like
to include the text of the copyright in the book, so that everything's
clear.

Thanks!

Arnold