# `kind` bit `0x2` is the FOCUSABLE flag — ✅ decoded, 0 violations disc-wide

**Status:** ✅ `CONFIRMED`, classification **decoded** — the field, plus a
disc-wide check. 2026-08-31.

## The claim

In the 60-byte UI declaration entry, `+0x28` is the **kind** word and `+0x2C` is
the **focus/nav index** (`−1` on anything that cannot take the cursor). They are
the same fact twice:

> **`kind & 0x2` is set if and only if the focus index is ≥ 0.**

**0 violations in 15 493 declaration entries across 24 UI paks** — every parseable
build in each. 1 062 focusable elements, 14 431 not.

[`data/kind-focus-bit-census.txt`](../data/kind-focus-bit-census.txt) ·
[`examples/kind_census_five_screens.rs`](../../../crates/sylpheed-formats/examples/kind_census_five_screens.rs)

| kind | focus `= −1` | focus `≥ 0` | | kind | focus `= −1` | focus `≥ 0` |
|---|---|---|---|---|---|---|
| `0x0` | 7 459 | 0 | | `0x2` | 0 | **16** |
| `0x1` | 1 093 | 0 | | `0x2002` | 0 | **16** |
| `0x4` | 2 964 | 0 | | `0x3002` | 0 | **778** |
| `0x5` | 282 | 0 | | `0x3003` | 0 | **192** |
| `0x8` | 650 | 0 | | `0x73002` | 0 | **64** |
| `0x9` | 6 | 0 | | `0x73003` | 0 | **96** |
| `0xC` | 48 | 0 | | | | |
| `0x10` | 329 | 0 | | | | |
| `0x14` | 2 | 0 | | | | |
| `0x3000` | **817** | 0 | | | | |
| `0x3001` | 10 | 0 | | | | |
| `0x3004` | 426 | 0 | | | | |
| `0x3008` | 72 | 0 | | | | |
| `0x300C` | 135 | 0 | | | | |
| `0x3010` | 38 | 0 | | | | |

Every value in the right-hand column has bit `0x2`; no value in the left-hand
column does.

## 🔴 So `kind == 0x3002` is not the test for a button

It catches **778 of 1 062** focusable elements and **misses 284 — 26.7 %**, at
`0x2`, `0x2002`, `0x3003`, `0x73002` and `0x73003`. And `0x3000`, which looks
like a button and appears **817** times, is **not** focusable.

**On the screens the port ships this is not hypothetical.** `GP_TITLE` entries 2
and 3 — the `PRESS Ⓐ BUTTON` plate composited over the title — declare
`ptbtn00.rat` as **`0x73002`**. An equality test drops it. So does the title's
`ptlogoall_eff.t32` / `ptlogoall_eff2.t32` at `0x3000` go the other way: an
equality test correctly leaves them out, but a `kind >= 0x3000` test would not.

## Why this is a decode and not a correlation

The two fields are independent bytes four apart in a record nobody wrote them
into together, and the test is **two-sided**: it would fail if any focusable
element lacked the bit *or* if any non-focusable element carried it. A
one-directional check ("every button has the bit") would have been satisfied by
the bit simply being common.

⚠️ **What is NOT claimed.** The other bits look like independent flags — `0x1`
where the crate reads "has a parent", `0x4` "a repeated instance of a template",
`0x10` a primitive — and `0x2000` / `0x3000` / `0x70000` like a group in the high
half. That is **observed structure, not decoded**: nothing here tests them, and
the `0x5`/`0x9`/`0xC`/`0x14`/`0x3001`/`0x300C` combinations are consistent with
flags without establishing them.

⚠️ **Reach.** Every `.pak` under `dat/` that `parse_build` accepts — 24 archives.
It says nothing about whether a *focusable* element is reachable by the cursor at
run time, only that the declaration marks it.

## Refutation attempt on `sylpheed-port` — survives in its scope, fails past it

Their `DECISIONS.md` records: *"Every sprite decoration on both screens is `0x0` —
`ptframe1`…`ptframe4` included — and every button is `0x3002`."*

✅ **On `GP_TITLE` entries 5 and 6, both halves are exactly right**, and this
census reproduces them independently — a third reading of the same field after
their exporter and my earlier declaration walk.

🔴 **One build over, both halves fail.** The census above is deliberately wider
than the claim in two ways, because a census that only looks where the claim
looks cannot fail it: it covers every element rather than only `.t32` sprites, and
every build rather than the two screens. Entry 4 — the **title**, which they say
they have not run yet — puts `ptlogo1`/`ptlogo2` at `0x4` and
`ptlogoall_eff`/`ptlogoall_eff2` at `0x3000`, and entries 2/3 put a button at
`0x73002`.

The claim was true of what it examined. What is refuted is its **reach**, and the
reach is what was about to be used.