Am 15.12.22 um 06:40 schrieb Nick Hastings:
Checking the files themselves I see that for most files third clause does indeed specify University of California, Berkeley and its contributors. However there are a handful of others that specify different people in the clause 3 and have correspondingly modified clause 4. So I guess I need to grind through and separate them all?
Yes. The NetBSD Foundation allows to relicense their files under BSD-4-clause to BSD-2-clause, see http://www.netbsd.org/about/redistribution.html For the rest of the files you would have to make separate BSD-4-clause variants, e.g. BSD-4-clause-Utah or BSD-4-clause-Adam-Glass.
