re: the leaderboard screen, and a Detail_* prefix trap

sub_8219E560 r11, censused against tables.pak exactly like the result screens.
444 instructions, one call site (sub_821A2A80), 100 % of its names are tables.pak
names.

The 18 names partition exactly: 13 record names + 5 field-only names.  The 13 are
the 12 Detail_* panel elements plus MISSIONS -- a 0-field record already owned by
isl-condition-builtins.md and challenge-mission-gate.md, so not new.  The five
field-only names are the screen's parameters: DETAIL_TITLE, one field in each of
six mode records (ScoreAttack, TimeAttack, Extra01..Extra04), and
Detail_Board_{Permanent,Monthly,Friend,Self}, four fields of CHIPS -- the board
scopes.

All 12 Detail_* record names are in the code block, zero residual -- the opposite
of the boss motions, where the block was a 25-of-55 subset.  The panel is Rank,
GamerTag, Main_{Time,Points}_{Self,Live}, Warships, Warplanes,
Weapon_{Nose,Main1,Main2,Main3}: your figure against the selected entry's, plus
that pilot's kills and four weapon slots.  _Live, GamerTag and the Friend/Monthly
boards make it the Xbox Live detail view.

The trap worth keeping: tables.pak has 12 Detail* RECORD names and 12 Detail*
FIELD names, and they are DISJOINT (0 overlap).  The fields are a different axis
-- 4 board scopes + 6 modes + Detail_Window_{Known,Unknown}.  A Detail_* name
means nothing until you say whether it is a record or a field.

Not settled: what Detail_Window_Known/_Unknown switch between, and whether
Extra01..04 map onto the four challenge missions.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE

docs/re/structures/leaderboard-screen.md

@@ -0,0 +1,62 @@
+# ✅ The leaderboard screen — `sub_8219E560`, and a `Detail_*` prefix trap
+
+- **Key list:** `sub_8219E560` `r11`, base `0x820A0000`, **18 names, 100 % of them
+  `tables.pak` names**; 444 instructions, **one** call site (`sub_821A2A80`).
+- **Related:** [[result-screens]] (the same compiled-key-list shape),
+  [[savegame-format]] (where that shape was first documented).
+
+## ✅ The 18 partition exactly
+
+| | |
+|---|---:|
+| `tables.pak` **record** names | **13** |
+| **field**-only names | **5** |
+
+`13 + 5 = 18`. The 13 are the **12 `Detail_*` panel elements** plus **`MISSIONS`**
+— a 0-field record already owned by [[isl-condition-builtins]] and
+[[challenge-mission-gate]] as an IDXD record key, not a new thing.
+
+The five field-only names say how the screen is parameterised:
+
+* **`DETAIL_TITLE`** — one field in **each of six mode records**: `ScoreAttack`,
+  `TimeAttack`, `Extra01`, `Extra02`, `Extra03`, `Extra04`.
+* **`Detail_Board_{Permanent, Monthly, Friend, Self}`** — four fields of `CHIPS`,
+  the four board scopes.
+
+✅ **And all 12 `Detail_*` record names are in the code block — zero residual.**
+That is worth stating because the boss motions went the other way: there the
+block was a 25-of-55 subset. Here the code names the whole population.
+
+## The detail panel — 12 elements
+
+```
+Detail_Rank            Detail_GamerTag
+Detail_Main_Time_Self  Detail_Main_Time_Live
+Detail_Main_Points_Self  Detail_Main_Points_Live
+Detail_Warships        Detail_Warplanes
+Detail_Weapon_Nose     Detail_Weapon_Main1/Main2/Main3
+```
+
+`_Self` beside `_Live` for both time and points, `GamerTag`, and Friend/Monthly
+boards — this is the **Xbox Live** leaderboard detail view: your own figure
+against the selected entry's, plus that pilot's kill counts and the four weapon
+slots they flew.
+
+## 🔑 The trap: two disjoint 12-element `Detail*` populations
+
+`tables.pak` has **12 `Detail*` record names and 12 `Detail*` field names, and
+they do not overlap at all** (0 of 12). The fields are a different axis entirely:
+
+```
+Detail_Board_{Permanent,Monthly,Friend,Self}      the four scopes
+Detail_{ScoreAttack,TimeAttack,Extra01..Extra04}  the six modes
+Detail_Window_{Known,Unknown}                     two window states
+```
+
+**A `Detail_*` name means nothing until you say whether it is a record or a
+field** — the same prefix indexes the panel's elements on one side and the
+screen's mode/scope selectors on the other. Counting "24 `Detail_*` things" would
+be counting two unrelated tables together.
+
+🟡 Not settled: what `Detail_Window_Known` / `_Unknown` switch between, and
+whether `Extra01…04` map onto the four challenge missions the corpus knows.