For every musician, there's a different way to do music. One of those ways is to use specific notations to indicate different ways to play a chord. In Nashville notation, certain symbols indicate the type of chord to be played.
- minor becomes -
- diminished becomes º
- augmented becomes +
- major seventh becomes ∆
- major becomes M
You can change a setting to change minor chords back to an "m" instead. To do this, go into the Utilities Menu by tapping on the gear icon in the Menubar. Next, open Settings > Display Settings > Song Formatting > Chords > Use Symbol Replacements and turn this off. Of course, alternately you can turn this on if you want these symbol replacements.