One tile: a value to set on the chapter dimension, and what to call it.
Position in the list, 0-based. Stable for as long as the scene is.
The value to hand setDimensionValue.
setDimensionValue
Human-readable label — an authored category, or a generated fallback.
Whether label came from the scene rather than being generated.
label
One tile: a value to set on the chapter dimension, and what to call it.