Pitch of a note is measured in semitones. MusiCAD translates this semitone-pitch into a textual representation using note-name, octave and alteration in the form of accidentals.
Note names can be A, B, C, D, E, F and G. Practical octave numbers range from 1 to 7 and accidentals used in text representation are # and b.
More specifically, default pitch is used to refer to the exact tuning of the note A4, usually 440Hz. Adjust MIDI-fine tuning in MIDI options dialog to change default pitch.