Resonator: the Notes a Chart Never Prints
Twelve roots, 24 types, and the half of a chart that is deliberately left blank.
Pick a root and one of 24 types and see it as it lies on this reader's neck, roots marked throughout. A number chart is a list of chords and bar counts; everything else that happens is somebody's decision, made in real time out of a map like this one.
The open tuning gives three of these notes for free; the rest are reached by moving the bar, which is why a player looks at where the scale lies rather than which grips it contains.
That silence is a feature. A chart that specified the notes would take an hour to write and would stop being readable at a count-off, which is the only thing it was ever for.