diff --git a/.changeset/search-auto-excluded-types-disjointness-pin.md b/.changeset/search-auto-excluded-types-disjointness-pin.md
new file mode 100644
index 0000000000..06c5c5c376
--- /dev/null
+++ b/.changeset/search-auto-excluded-types-disjointness-pin.md
@@ -0,0 +1,31 @@
+---
+"@objectstack/spec": patch
+---
+
+fix(spec): 把 `$search` 自动默认集三个类型词表的「互不相交」钉成受检事实 (#6934)
+
+`packages/spec/src/data/search-fields.ts` 的 `autoDefaultFields` 先测一遍
+`SEARCH_AUTO_EXCLUDED_TYPES` 的**否定**守卫，紧接着才是
+`SEARCHABLE_TEXTUAL_TYPES` / `SEARCHABLE_ENUM_TYPES` 的**肯定**白名单。三个集合
+今天两两不相交，所以那行否定守卫改变不了任何一次判定 —— 在完整的 56 个字段类型
+域（`FieldType` 枚举 ∪ 三个词表 ∪ 域外探针）× 9 种调用形态 = 504 次解析上逐一比对，
+删掉它与保留它的结果**逐字节相同**。本次改动因此**不改变任何行为**。
+
+**保留该行，而不是退休它。** 判据是构造出来实测的，不是判断的：给
+`SEARCHABLE_TEXTUAL_TYPES` 补一个已在排除集里的类型（`json`），两种形态给出的是
+**方向相反、同样沉默**的两种解决 —— 有守卫时该类型被悄悄踢出扫描（fail closed），
+没守卫时肯定列表获胜，该类型不仅进入自动默认集，还顺带进入上一层 #4254 的 ingress
+allow-list，于是 `$searchFields=<该字段>` 从「拒绝」翻成「接受」，正是 #4483 为 `id`
+关掉的那类放宽。排除集里写着 `secret` / `password` / `encrypted` / `vector`，
+fail open 意味着对被脱敏或重量级列做 `$contains` 子串扫描。所以那行不是安全网
+（两个方向都不出声），但它是**更安全的那个平局裁决**。
+
+**真正堵住这一类的是钉子。** `search-fields.test.ts` 新增：三个词表两两不相交的
+断言，加上两个方向的行为断言（排除集成员必被拒、白名单成员必被纳）。任一方向出现
+重叠都会变红，且没有任何单点放宽能让它变成空转 —— 已用临时重叠实测两种形态各自
+变红。同时补充：两个肯定列表之间也必须不相交，因为引擎侧
+`fieldClausesForTerm` 先分支到 `SEARCHABLE_ENUM_TYPES`，同时命中的类型只会走
+option label 映射、永远不会按原文 `$contains` 检索。
+
+守卫处的注释如实写明它是 redundant-by-construction、不承重、以及保留它买到的是
+哪个方向，避免下一位作者把它读成「新增可搜索类型时必须同步维护排除集」的规则。
diff --git a/packages/spec/src/data/search-fields.test.ts b/packages/spec/src/data/search-fields.test.ts
index 8011bee622..98208bbf09 100644
--- a/packages/spec/src/data/search-fields.test.ts
+++ b/packages/spec/src/data/search-fields.test.ts
@@ -5,6 +5,9 @@ import {
   resolveSearchFieldResolution,
   resolveSearchFields,
   SEARCH_AUTO_EXCLUDED_FIELDS,
+  SEARCH_AUTO_EXCLUDED_TYPES,
+  SEARCHABLE_ENUM_TYPES,
+  SEARCHABLE_TEXTUAL_TYPES,
 } from './search-fields';
 
 // ---------------------------------------------------------------------------
@@ -118,3 +121,69 @@ describe('[#4483] $search auto field set — lead orders, never admits', () => {
       .toEqual([]);
   });
 });
+
+// ---------------------------------------------------------------------------
+// [#6934] The three search type vocabularies stay PAIRWISE DISJOINT.
+//
+// `autoDefaultFields` tests `SEARCH_AUTO_EXCLUDED_TYPES` immediately before the
+// positive `SEARCHABLE_TEXTUAL_TYPES` / `SEARCHABLE_ENUM_TYPES` allow-list. With
+// the sets disjoint that guard cannot change an outcome — measured over the full
+// field-type domain, deleting it moves not one resolution. It is kept as the
+// fail-closed tiebreak (reasons at its site); these tests are what make the
+// disjointness a CHECKED fact instead of a coincidence.
+//
+// Why both halves are here. A type declared in the excluded set AND in a
+// positive list is a contradiction that resolves SILENTLY in either shape:
+// dropped from the scan with the guard, admitted to the scan — and to the #4254
+// ingress allow-list — without it. Neither is a diagnostic the author ever sees.
+// These assertions are. The set assertions name the contradiction directly; the
+// two resolution assertions below go red on an overlap independently of them,
+// and in opposite directions, so no single relaxation can make this pin vacuous.
+// ---------------------------------------------------------------------------
+describe('[#6934] search type vocabularies are pairwise disjoint', () => {
+  const overlap = (a: ReadonlySet<string>, b: ReadonlySet<string>) =>
+    [...a].filter((t) => b.has(t)).sort();
+
+  it('no type is both auto-excluded and on a positive allow-list', () => {
+    expect(
+      overlap(SEARCH_AUTO_EXCLUDED_TYPES, SEARCHABLE_TEXTUAL_TYPES),
+      'a type cannot be both auto-excluded and searchable-textual',
+    ).toEqual([]);
+    expect(
+      overlap(SEARCH_AUTO_EXCLUDED_TYPES, SEARCHABLE_ENUM_TYPES),
+      'a type cannot be both auto-excluded and searchable-enum',
+    ).toEqual([]);
+  });
+
+  it('the two positive allow-lists share no type either', () => {
+    // Not cosmetic: the ENGINE branches on `SEARCHABLE_ENUM_TYPES` FIRST
+    // (`fieldClausesForTerm`, objectql `search-filter.ts`), so a type in both
+    // would be searched by option-label mapping and never as raw `$contains`.
+    expect(
+      overlap(SEARCHABLE_TEXTUAL_TYPES, SEARCHABLE_ENUM_TYPES),
+      'an enum type is searched by label mapping, a textual one by $contains',
+    ).toEqual([]);
+  });
+
+  it('every auto-excluded type is REJECTED by the auto-default', () => {
+    // Goes red if an overlap resolves the positive way (i.e. if the guard is
+    // dropped while the sets intersect).
+    for (const t of SEARCH_AUTO_EXCLUDED_TYPES) {
+      expect(
+        resolveSearchFieldResolution({ fields: { probe: { type: t } } }),
+        `'${t}' is auto-excluded but the auto-default admitted it`,
+      ).toEqual({ allowed: [], source: 'auto' });
+    }
+  });
+
+  it('every searchable type is ADMITTED by the auto-default', () => {
+    // Goes red if an overlap resolves the negative way (the guard silently
+    // dropping a type an author has just declared searchable).
+    for (const t of [...SEARCHABLE_TEXTUAL_TYPES, ...SEARCHABLE_ENUM_TYPES]) {
+      expect(
+        resolveSearchFieldResolution({ fields: { probe: { type: t } } }),
+        `'${t}' is declared searchable but the auto-default rejected it`,
+      ).toEqual({ allowed: ['probe'], source: 'auto' });
+    }
+  });
+});
diff --git a/packages/spec/src/data/search-fields.ts b/packages/spec/src/data/search-fields.ts
index 982d8aecb5..db733c3e4c 100644
--- a/packages/spec/src/data/search-fields.ts
+++ b/packages/spec/src/data/search-fields.ts
@@ -69,6 +69,30 @@ function autoDefaultFields(fields: Record<string, SearchFieldMeta>, displayField
     if (!meta || meta.hidden) return false;
     const t = meta.type;
     if (!t) return false;
+    // Redundant BY CONSTRUCTION, and kept deliberately (#6934).
+    //
+    // `SEARCH_AUTO_EXCLUDED_TYPES` is disjoint from both positive lists, so
+    // every type it names already falls through the `return` below as `false`
+    // — identically to a type in none of the three sets (`number`, `date`, …).
+    // Measured over the full 56-type domain (`FieldType` ∪ all three
+    // vocabularies), deleting this line moves not one resolution. So it is NOT
+    // load-bearing: adding a type to `SEARCHABLE_TEXTUAL_TYPES` does not also
+    // require keeping it out of this set for the auto-default to reject it.
+    //
+    // What it buys is the DIRECTION the two vocabularies resolve in should that
+    // disjointness ever break. Both directions are silent — the guard is no
+    // safety net, it is a second tiebreak — but they are not equally bad. WITH
+    // it, an overlapping type is dropped from the scan (fail closed). WITHOUT
+    // it the positive list wins and the type enters the auto-default AND, one
+    // layer up, the #4254 ingress allow-list — so `$searchFields=<that field>`
+    // flips from refused to ACCEPTED, the same widening #4483 closed for `id`.
+    // This set names `secret`, `password`, `encrypted` and `vector`: failing
+    // open there means a `$contains` scan over a masked or heavy column.
+    //
+    // The disjointness is not left to coincidence. `search-fields.test.ts` pins
+    // all three vocabularies pairwise disjoint AND pins both resolution
+    // directions, so an overlap is a red test rather than a silent tiebreak
+    // whichever way it lands.
     if (SEARCH_AUTO_EXCLUDED_TYPES.has(t)) return false;
     return SEARCHABLE_TEXTUAL_TYPES.has(t) || SEARCHABLE_ENUM_TYPES.has(t);
   });