Interface AutoColorLegendEntry

Set (true) only for a synthetic "absence" bucket — e.g. "No classification" or "Not in this system" — rather than a real distinct value drawn from the model. Consumers that group/filter/export values should not treat name as a classification code, material name, etc. when this is set.

Forward compatibility: an older consumer that doesn't know this field simply renders the entry like any other legend row. That's safe, not silently wrong: the name text ("No classification") is self-describing and the entry behaves like a normal clickable/isolatable row — it just can't be told apart from a real value by an older UI's styling.