On Tue, 18 Jun 2024, segaloco via TUHS wrote:
[...]
The story I've gotten is AT&T policy was to
release odd-numbered
versions, so PWB 1.0, System III, and System V made it out into the
world, PWB 2.0 and Release 4.0 stayed in the labs. In the most
technical sense, System IV never existed, what could've become it
remained a Bell System-only issue.
Thanks; I'd forgotten about AT&T's "odd-only" policy.
-- Dave