docs/re: the declaration table is not a paint order on every screen

Building the Explorer's UI Screens browser turned up a limit on a claim the
format doc states flatly. `ui-rat-layout.md` says the element declaration table
is the screen's back-to-front draw list, verified 11/11 on the tutorial pause
bundle -- and that reproduces exactly here. `GP_TITLE.pak` build 7 does not:
painting in declaration order puts the full-screen background art (element 13)
over the wordmarks (elements 0-5).

Ruled out rather than guessed at: there is no depth key in the 60-byte entry.
Across the title build's 30 entries every unknown word is constant, and `+36`
-- the one that varies -- is an instance index on the `kind = 0x4` repeated
entries, not a layer.

Recorded as an open item with the cheapest next step (composite two more
screens that have both a background and overlapping foreground, and check
whether their background sits adjacent to a `kind = 0x10` PRMD entry as the
title's does). The viewer paints in declaration order and does not paper over
it, so a screen whose background lands on top is showing this bug rather than
a decode failure.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/re/BACKLOG.md

@@ -6,6 +6,51 @@ unknown, what evidence exists, and what the first step would be. Move an item in
 
 ---
 
+## The declaration table is not a paint order on every screen
+
+**Found 2026-08-17**, building the Explorer's UI Screens browser on
+[`ui_layout`](structures/ui-rat-layout.md). **Status: 🔎 open — the pause menu is
+right, the title screen is not.**
+
+`ui-rat-layout.md` says the bundle's element declaration table lists elements
+"in back-to-front order", verified 11/11 on the tutorial pause bundle. That
+holds — the tutorial and in-mission PAUSE builds both composite correctly, and
+`pgpeff02a` → parent 3 / `pgp_ttrl_btn10` at (546,288) / the 70 px button pitch
+all reproduce exactly.
+
+**`GP_TITLE.pak` build 7 does not.** Painting in declaration order puts
+`ptbase2.t32` (the full-screen background art, element **13**) *on top of* the
+`ptlogo1`/`ptlogo2` wordmarks (elements **0–5**), which the real title screen
+obviously does not do. The pause bundles never caught this because their
+elements barely overlap.
+
+**What has been ruled out:** there is no depth/layer key in the 60-byte
+declaration entry. Dumping every word across the title build's 30 entries, the
+unknown fields are constant — `+28` is 0 everywhere, `+44` is `0xffffffff`
+everywhere, `+56` is 0 everywhere — and `+36`, which the doc lists as
+`0xffffffff`, is not a depth either: it is `0`/`1` **only** on the `kind = 0x4`
+repeated-instance entries (`ptlogo1`/`ptlogo2` copies), i.e. an instance index.
+So the order is not recoverable by sorting the table on any field it carries.
+
+**What that leaves.** The background group is contiguous — elements 12, 13, 14
+are `pteff00.prm`, `ptbase2.t32`, `pteff04.t32`, and 12 carries `kind = 0x10`,
+a flag no pause element has (theirs are `0x0` / `0x1` / `0x3002`). `pteff02.prm`
+at 17 has it too. So `0x10` marking a `PRMD` primitive, and primitives opening a
+layer that draws beneath what precedes them, is the cheapest hypothesis — but it
+is a **hypothesis**, and "draw the `.prm` group first" would fit this one screen
+without being evidence of anything.
+
+**First step:** composite `GP_MISSION_SELECT` / `GP_READY_ROOM` / `GP_OPTIONS`,
+which have both a background and overlapping foreground elements, and see
+whether their background sits at a `0x10`-adjacent index too. Two more screens
+agreeing turns the hypothesis into a rule; one disagreeing kills it. The
+Explorer's `screen render`/`screen info` commands make that a minute's work per
+screen, and the per-element visibility toggles isolate a suspect element.
+
+**Meanwhile** the viewer paints in declaration order and does not pretend
+otherwise — a screen whose background lands on top is showing you this bug, not
+a decode failure.
+
 ## Capital ships assemble wrong in the viewer
 
 **Reported:** 2026-07-30, by the user. **Status:** ✅ **format-side cause found and