There is no need for them to do that because it's established by the player/pose whether the back is apple or forest green. All of the
forest green Sovereigns are print group 1 or 2 subjects and all of
the apple green Sovereigns are print group 3 or 5 subjects.
Here are the checklists for both.
http://t206resource.com/Sovereign%20...Checklist.html
http://t206resource.com/Sovereign%20...Checklist.html
here's a thread where Jim Rivera discovered that there was a difference in
the Sovereign 350's.
http://www.net54baseball.com/showthread.php?t=112571