A standard DAD Mountain Dulcimer Tuning has frets that create a Mixolydian scale on each fretted string. The current tuning in Dorico tunes each string to a major scale instead; so it interprets a C# on the D string as fret 6, and the existing C-natural as a question mark.
I have altered the tuning so that the subtonic tone on each string will correctly indicate the 6th fret on the dulcimer TAB, and share that tuning here.
dulcimerStandardTuning.zip (561 Bytes)
(I had to ZIP the file to post it here.)
P.S. I tried to add the customary added frets, 1.5 (1+) and 6.5 (6+) now used in many dulcimers, but since Dorico does not allow the renaming of the frets and is unlikely to do so, adding these frets throws off the rest of the numbering and makes the TAB unusable. For my own purposes, the best solution has been to export to PDF and add the resulting special fretting numbers there.