[TUHS] Tree of late BSD releases

[dds@aueb.gr (Diomidis Spinellis)]

For reconstructing Unix history on a single repository [1], I'd need to 
represent the branches, merges, and chronological sequence of the late 
BSD releases (after 4.3).  However, I've found on the internet some 
conflicting and simplistic information, so I'd welcome your input on how 
to straighten things up.

First, consider this widely reproduced BSD family tree [2].  It has 
4.4BSD-Encumbered derive from a line that includes Net/1, which was 
freely redistributable.  Wouldn't it be clearer to create two branches, 
one with distributions free of AT&T code (4.3 BSD Net/1, 4.3 BSD Net/2, 
4.4 BSD Lite1, 4.4 BSD Lite2) and one with full distributions (4.4 BSD, 
...)?  On which side would Tahoe and Reno stand?

Also, the same tree [2] shows 4.4 BSD having as its ancestor 4.3 BSD 
Net/2, whereas another tree depicted on Wikipedia [3] has shows 4.4 BSD 
and 4.3 BSD Net/2 having as their ancestor 4.3 BSD Reno.  What's the 
correct genealogy?

Finally, I have a conflict with release dates.  Wikipedia gives the 
following dates for Tahoe and Net/1 [4]:

4.3 BSD Tahoe June 1988
4.3 BSD Net/1 June 1989

However, looking at time-stamp of the newest files available under the 
corresponding directories in the CSRG CD-ROMs [5] I find the opposite order:

cd2/net.1/sendmail/src/util.c 1989-01-01 12:15:58
cd2/4.3tahoe/usr/src/sys/tahoevba/vx.c 1989-05-23 13:47:43

What's the actual time sequence, and what's the corresponding genealogy?

[1] https://github.com/dspinellis/unix-history-repo
[2] 
http://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/share/misc/bsd-family-tree
[3] https://en.wikipedia.org/wiki/File:Unix_history-simple.svg
[4] https://en.wikipedia.org/wiki/Berkeley_Software_Distribution
[5] https://www.mckusick.com/csrg/

Many thanks,

Diomidis Spinellis

PS Thank you all for the help you've provided so far.