diff --git a/recognization/docs/research/2026-09-28-recognition-architecture/DECISION.md b/recognization/docs/research/2026-09-28-recognition-architecture/DECISION.md
index cc216fd..618d048 100644
--- a/recognization/docs/research/2026-09-28-recognition-architecture/DECISION.md
+++ b/recognization/docs/research/2026-09-28-recognition-architecture/DECISION.md
@@ -901,8 +901,10 @@ out of "210g"), and percentages are excluded because "カロリー 50% カット
 claim about the contents. Measured on the corrected labels, full resolution:
 precision 86% -> 91%, false accepts 8 -> 5, coverage unchanged at 79%.
 
-
 ### Far unknowns: the accept lines were tuned on a shelf that has no unknowns
+
+Every threshold in this document was fitted on image6, where each crop is a
+facing of a product the shelf actually holds. That is a closed-set tuning set,
 and it hid the far-unknown rate completely: the shipped lane accepted 82 of
 2650 crops from 60 Wikimedia Commons supermarket photos of milk, soy and snack
 shelves - 3.09 %, against G3's 1 %.