diff --git a/.changeset/29801-related-list-placement-skill.md b/.changeset/29801-related-list-placement-skill.md
new file mode 100644
index 00000000000..b43fb73bcbe
--- /dev/null
+++ b/.changeset/29801-related-list-placement-skill.md
@@ -0,0 +1,12 @@
+---
+'@objectstack/skills': patch
+---
+
+docs(skills): objectstack-data teaches `relatedList` placement by each value's role, not by record-page tabs or columns
+
+Clause-②: no
+Metadata-protocol: none
+
+- **Before.** `rules/relationships.md` said `relatedList: 'primary'` draws "a full-width table in the details column after the first field section (in the Details tab, no tab of its own)" and that `true` / omitted is "a side card (the shared **Related** tab)". The spec's `relatedList` describe no longer names any tab or column, so the skill taught a page layout the record page does not draw.
+- **Now.** The three bullets follow the spec describe: `'primary'` is part of the record's main content, a full-width table in the record's detail body (still the default for an inline-edited `master_detail` FK); `false` means the child object is not shown on the parent record page; `true` or omitted is an auxiliary panel on the record page. Layout stays ADR-0085's to define.
+- The file gets smaller and stays under its token ceiling; no ceiling moves, no schema, key or behaviour changes.
diff --git a/skills/objectstack-data/rules/relationships.md b/skills/objectstack-data/rules/relationships.md
index 1b06e63d635..442a42b9966 100644
--- a/skills/objectstack-data/rules/relationships.md
+++ b/skills/objectstack-data/rules/relationships.md
@@ -335,12 +335,11 @@ audit_ref: { type: 'master_detail', reference: 'invoice', relatedList: false },
 
 `relatedList` is tri-state — placement (ADR-0085):
 
-- `'primary'` — main content: a full-width table in the details column after
-  the first field section (in the Details tab, no tab of its own). Default for a
-  `master_detail` FK with `inlineEdit`.
-- `false` — hidden from the parent's page.
-- `true`, or omitted (except inline-edited `master_detail`) — a side card
-  (the shared **Related** tab).
+- `'primary'` — part of the record's main content: a full-width table in the
+  record's detail body. Default for a `master_detail` FK with `inlineEdit`.
+- `false` — the child object is not shown on the parent record page.
+- `true`, or omitted (except inline-edited `master_detail`) — an auxiliary
+  panel on the record page.
 - Order is the parent's: `relatedLists: ['task', 'event.related_to']` (child, or
   `object.field`) lists those first. A child in the stack with no inbound FK is
   refused everywhere; one that exists nowhere is refused by `os validate` /