diff --git a/.claude/skills/deploy/SKILL.md b/.claude/skills/deploy/SKILL.md
index cefb8ec..1e37dae 100644
--- a/.claude/skills/deploy/SKILL.md
+++ b/.claude/skills/deploy/SKILL.md
@@ -48,8 +48,25 @@ cd ios     && fastlane latest_builds
 ```
 
 Repeat the Play query for `internal` and `alpha` if anything might be parked
-there. Take the **highest build number seen on any track of either store** and
-go above it.
+there.
+
+The two stores do not agree and never have — at the time of writing Play
+production was on `1.0.5+7` while the App Store was live on `1.0.6+8`. Read
+both; do not infer one from the other.
+
+The rules differ by platform:
+
+- **Play**: the version code is global to the app. It must exceed the highest
+  code on *any* track, full stop.
+- **App Store**: `CFBundleVersion` uniqueness is scoped to the
+  `CFBundleShortVersionString` train. Build 8 under a new `1.1.0` does not
+  collide with build 8 under `1.0.6`. This is why `latest_builds` reports the
+  live *version string* and not just the number — the number alone cannot
+  decide the question.
+
+Taking the highest build number seen anywhere and going above it is always
+safe. Reusing one is only safe on iOS, only under a new version string, and
+never on Play.
 
 Known non-problems:
 
diff --git a/RELEASING.md b/RELEASING.md
index 528b98d..7d0538f 100644
--- a/RELEASING.md
+++ b/RELEASING.md
@@ -68,8 +68,16 @@ backstop, not as an invitation.
    ```sh
    cd android && fastlane run google_play_track_version_codes track:production
    cd android && fastlane run google_play_track_release_names  track:production
+   cd ios     && fastlane latest_builds
    ```
 
+   Check both stores -- they drift apart. Play production was on `1.0.5+7`
+   while the App Store was live on `1.0.6+8`. Play version codes are global to
+   the app and must always increase; iOS scopes build numbers to the version
+   string, so a build number may recur under a new version name (which is why
+   `latest_builds` reports the live version string too). Going above the
+   highest number seen anywhere is always safe.
+
    (A track with no releases fails with `undefined method 'flat_map' for nil`
    rather than returning empty -- that is a fastlane bug, not a permissions
    problem.)