diff --git a/docs/re/BACKLOG.md b/docs/re/BACKLOG.md
index eabeccc..d3cd4e5 100644
--- a/docs/re/BACKLOG.md
+++ b/docs/re/BACKLOG.md
@@ -337,6 +337,12 @@ search cannot find a *schedule*.
 
 **Places searched so far:**
 
+* ❌ **`REGN` is EXCLUDED as the wave scheduler (2026-08-26)** — it is a
+  tetrahedral navigation mesh (vertices, faces with planes and adjacency,
+  tetrahedra with portal costs, a grid indexing which tets fall in each cell).
+  Every section is accounted for; there is no time field, no unit reference and
+  no trigger anywhere in it. It was chased here because "a scheduler would be
+  indexed by a grid" — a guess from shape, and the shape was pathfinding.
 * ✅ **`hidden/MiscBin.pak` — new to the corpus.** 11 `REGN` + 11 `MCOL` objects,
   none name-resolved. `REGN`'s header is now decoded: a per-map **uniform spatial
   grid** (bbox, cell size, 5³ or 10³ cells), self-checked 11/11. Its four data
diff --git a/docs/re/structures/regn-map-grid.md b/docs/re/structures/regn-map-grid.md
index bfe0c7c..b7d2f49 100644
--- a/docs/re/structures/regn-map-grid.md
+++ b/docs/re/structures/regn-map-grid.md
@@ -131,6 +131,23 @@ thing is indexed *by*.
 partition and no more; the sections are unread. Treat this as the location of the
 world's spatial data, not as the wave table.
 
+> ❌ **SETTLED 2026-08-26 — `REGN` is not the wave scheduler, and cannot be.**
+> It is a **tetrahedral navigation mesh**: vertices, faces with plane equations
+> and adjacency, tetrahedra with portal costs between their face pairs, and a
+> grid that indexes which tetrahedra fall in each cell. Every section is
+> accounted for by that structure. There is nowhere in it for "what spawns, when,
+> on what trigger" to live — no time field, no unit reference, no trigger.
+>
+> The hedge above was right to keep the reading provisional, but the reasoning
+> it hedged ("a grid is what a scheduler would be indexed by") was a **guess from
+> shape**, and the shape belonged to pathfinding. Worth noting because that guess
+> is what pointed this whole investigation at `REGN` in the first place.
+>
+> The wave-scheduler search should now treat `REGN` as **excluded**, not as
+> unread. The arrival timetable already found in `Route_S<NN>.tbl` — keyframed
+> `(time, quat, pos)` per squadron per phase, with `t` in seconds — remains the
+> only located part of that mechanism.
+
 ## ✅ Update: `REGN` is a stage's **MapPath**
 
 The per-stage definition record (see