diff --git a/docs/re/METHOD.md b/docs/re/METHOD.md
index 5ef1518c..2b10a61f 100644
--- a/docs/re/METHOD.md
+++ b/docs/re/METHOD.md
@@ -494,6 +494,21 @@ agent's loop prompt, i.e. nowhere durable. See [`README.md`](README.md) for the
   **author** a value that is decoded. **When sweeping for stale text, rank
   instructions above descriptions**: a wrong description misleads a reader, a wrong
   instruction produces a wrong *result* that looks like evidence.
+  📌 **Sweep the surface in BOTH directions.** Documented → does it exist, and
+  **parsed → is it documented**. `sylpheed-port` ran the second and found three
+  live undocumented flags, one of which (`--no-hold`) plays a screen past its rest
+  — *"a capability that exists only in an 11 000-line record is, to anyone reading
+  the interface, a capability that does not exist."* The mirror here: **41 env vars
+  read by `crates/`, 22 undocumented** — 7 example-only scratch, **15 live in
+  `src/`**, all in the mesh and texture lanes, none in the UI path
+  ([`data/env-var-surface.txt`](data/env-var-surface.txt)). Both directions
+  enumerate, so both **complete rather than sample** — which is rare enough in this
+  file to be worth choosing sweeps of that shape when one is available.
+  ⚠️ **And neither direction establishes that the thing WORKS.** They documented
+  `--no-hold` and it was inert under an interaction with `--time` — caught only by
+  running the example. I verified none of my 15 end to end and have said so rather
+  than implying coverage.
+
   📌 **And rank SILENT instructions above LOUD ones** (`sylpheed-port`'s
   refinement, from finding all of theirs were the loud kind): a wrong path errors
   out and announces itself; **an inert environment variable returns a clean, wrong
diff --git a/docs/re/data/env-var-surface.txt b/docs/re/data/env-var-surface.txt
new file mode 100644
index 00000000..426a51d7
--- /dev/null
+++ b/docs/re/data/env-var-surface.txt
@@ -0,0 +1,37 @@
+# The environment-variable surface, both directions. 2026-08-30.
+#
+# sylpheed-port swept documented -> parsed and found three live-but-undocumented
+# flags, noting that a capability documented only in an 11 000-line record is, to
+# anyone reading the interface, a capability that does not exist. This is the
+# mirror on my side: every env var the CODE reads, checked against the docs.
+# Like theirs it ENUMERATES, so it completes rather than samples.
+#
+#   41 environment variables read by crates/
+#   19 documented
+#   22 NOT documented, splitting cleanly:
+#
+#      7 read only in examples/ -- per-example output filters and dump paths.
+#        KF_SHOW, MAX_PAD, OUT_DIR_X, SUPPRESS_SUBSTR, SYLPH_RAW,
+#        VOICE_CHUNK_DUMP, DUMP_XPR_DIR
+#        Scratch. Reachable only by editing an example's command line.
+#
+#     15 read in src/ -- LIVE capabilities of the library and CLI:
+#        mesh / 3D   XCOLORSUB XDUMPHDR XDUMPVERT XMESHDBG XMIRROR XNODEDUMP
+#                    XNODEXFORM XONLYSUB XSPANHIDE XSPANONLY
+#        texture     XPR_FORCE_ENDIAN XPR_NO_BC_DWORD_SWAP XPR_NO_DETILE
+#                    XPR_NO_ENDIAN XPR_RES_INDEX
+#
+# ✅ FOR THE PORT: none of the 15 is in the UI path. Every env var ui_layout.rs
+# and the screen commands read is documented -- SYLPHEED_REST_RULE and
+# SYLPHEED_KF_TIME_LEGACY. The menu lane is clean in this direction.
+#
+# ⚠️ The five XPR_* are TEXTURE DECODE toggles and the port consumes textures. If
+# a sprite comparison ever disagrees, these are the knobs, and they are invisible
+# from the interface.
+#
+# 🔴 LIMIT, stated rather than glossed: I verified NONE of the 15 end to end.
+# `texture export` takes a loose file and the disc keeps its textures inside paks,
+# so the check cost more than the answer was worth in this iteration. That matters
+# because sylpheed-port found `--no-hold` PARSED, DOCUMENTED and INERT under an
+# interaction with `--time`: "parsed and reachable" is not "works". So the honest
+# claim is that 15 undocumented env vars are READ, not that 15 capabilities exist.