Signed: <0 penetration depth, >0 gap.
mesh / estimate, or empty for a run recorded before the field existed.
Bare IfcGUID of element A, or empty when the element has none (synthetic key).
Title of the group this clash was clustered into, when groups were computed.
The adapter's durable key — IfcGUID, IfcGUID:occurrence, expressid:… or a USD prim path.
Contact point (hard) or closest-point midpoint, in the run's world frame.
Coordinator triage (open / resolved / accepted); open when never reviewed.
ISO-8601 instant of the last review edit; empty when never reviewed.
Detection classification: hard / clearance / touch.
Clash.id— durable within a run (two keys + rule).