Catch-all so that “exactly one member is true” holds for this cluster. It is not a bare “other”: it names the concrete escapes the curated literature leaves open — spillover outside the Huanan market (upstream in the same wildlife trade, or geographically distant with later introduction into Wuhan), and a research-related incident at a Wuhan institution other than the WIV. Both are compatible with the whole curated observation set, because every market-side observation (O-1..O-5) is sampled at Huanan and every research-side observation (O-11, O-12) concerns the WIV/EcoHealth DEFUSE consortium specifically; neither dataset can see outside its own frame.