The circles indicate finger positions. The numbers indicate the preferred finger for playing the note. Fingers are numbered 1 for the index finger through 4 for the pinkie. The thumb is a T.
Chords that extend more than five frets from the nut are shown relative to a fret. The roman numeral at the lower left of the diagram is the relative fret for that diagram.
If a string in not to be played, it is a white line.
