diff --git a/.gitignore b/.gitignore
index d1c3ae91..b6afbe4d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,14 @@ __pycache__/
 # ── The port ────────────────────────────────────────────────────────────────
 # Generated from the user's own disc. This repo stays clean-room: code, schemas,
 # authored mappings and documentation only -- never game content.
+#
+# BOTH names are ignored on purpose. `export/` is what the exporter writes and
+# what `ExportTree.locate()` reads today; `data/base/` is the name MODDING.md
+# gives that same tree. Only one of them existed here, and it was the one
+# nothing writes -- so the live output directory was tracked while MISSION §4
+# said it was ignored. Ignoring both means renaming the tree to match the docs
+# cannot silently start committing the disc.
+/export/
 /data/base/
 # Transient inter-agent files. Deliberately outside history: they are working
 # artefacts with provenance in their manifest, not results.