DS+Protocol: Add "U" = Unknown stem source
Source. The manual is silent on what to do when there is uncertainty
about the source of planted material. Should we allow multiple guesses,
or should we allow one guess with an indication of uncertainty (eg a ?)?
Adding a column for certainty of origin might help. I favor the addition
of a column for uncertainty. What would you folks prefer?
Action Item: All respond to Michael with preferences, who will collate
them, make a decision, and implement it in the Manual and on the