I'm reading a paper on music theory and I keep coming across names of chords expressed as a fraction - I/I, I/V, ii/I, etc. Based on the use of these names in the paper, I'm reading this as:
I/I: A major chord with root as the first note of the Ionian mode of the diatonic major scale.
I/V: A major chord with root as the first note of the Mixolydian mode of the diatonic major scale.
ii/I: A minor chord with root as the second note of the Ionian mode of the diatonic major scale.
Is my understanding correct? Is there a more efficient/complete way to read this notation? In case I want to see more examples and explanation of this, what should I search for?
Thanks!