Evidence states for physical-product requirements.

Most product-development friction comes from treating different levels of certainty as if they were equivalent.

Confirmed

Usable supported specification—not a confidence score.

Partial

A real direction exists, but one or more important details remain open.

Deferred

The team intentionally assigns the final value to a supplier, engineer, laboratory or compliance specialist.

Inferred

A plausible interpretation that still needs confirmation.

Missing

No usable value exists yet.