These abbreviations are being used in Chords:
number of a tone in the diatonic scale or the symbol of an interval (3 = third).
added, for instance add4, a fourth added to the chord.
Aeolian, natural minor scale, sometimes written as eolian.
altered, a raised or lowered tone that, as a result, no longer belongs to the main key.
diminished, a minor or perfect interval lowered by a half tone.
Dur-Moll (durmoll), German, 6th tone in a minor scale raised by a half tone.
dominant, standard chord on the fifth tone of the diatonic scale.
German sixth, augmented 6th chord, first inversion of the double diminished 7th chord.
French sixth, augmented 6th chord, second inversion of the hard diminished 7th chord.
harmonic, usually the harmonic minor scale.
Italian sixth, augmented 6th chord, first inversion of the double diminished 6th chord.
Moll-Dur (molldur), German, 6th tone in a major scale lowered by a half tone.
N (or n)
Neapolitan, lowered 2nd tone in a diatonic scale.
as in no5, the 5th of the chord is missing.
incomplete, a chord missing one or more tones. C7no5 is an incomplete chord.
Picardy third. Major third on the tonic of a minor scale at the end of a musical section.
suspended, a 2nd or a 4th (temporarily) replaces the 3rd of (or is added to) a chord.
Special symbols, as used in the modern notation of chords:
augmented chord, C±
diminished chord, B—
half diminished chord, FŸ‡
augmented, a major or perfect interval raised by a half tone.