What it means
Any engine matching on titles merges these two and reports a price comparison between two different things. That failure is invisible to the person reading it, which is what makes it worse than returning nothing.
The closest any two photographs in this index get without being merged is 12 bits. The threshold is 10. That margin is the whole safety budget of the method, and it is narrower in the live index than in the held-out calibration set, where the nearest true negative sat at 16.
Published because the boundary is where a matching method is either honest or not, and nobody shows theirs.
Scope. This comes from one catalogue of 376 products. It is a real property of these listings, not evidence about the wider market, because no second store is connected yet.