diff --git a/README.md b/README.md
index 073bf9f..1613be5 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ normatively in
 items/
 └── <slug>/                     # ONE self-contained item per directory
     ├── listing.yaml            # storefront wrapper
-    ├── blueprint.yaml          # composition graph (see COMPONENT items below)
+    ├── blueprint.yaml          # composition graph; absent for a COMPONENT item
     ├── components/
     │   └── <name>.yaml         # ≥1; every file referenced by blueprint.yaml
     └── media/                  # optional assets
@@ -38,7 +38,9 @@ These are hard requirements. A violation is rejected when the platform syncs
 this repo:
 
 - the directory name equals both `listing.yaml`'s and `blueprint.yaml`'s
-  `metadata.slug`, and their `metadata.revision` values match;
+  `metadata.slug`;
+- the listing's `spec.itemType` is `BLUEPRINT` exactly when the item holds a
+  `blueprint.yaml`, and `COMPONENT` otherwise;
 - every blueprint node's `componentRef` resolves to a `components/<name>.yaml`
   file **in the same item directory**, and every such file is referenced — no
   unreferenced components;
@@ -52,8 +54,9 @@ this repo:
   a readiness probe for a public endpoint; `WORKER`, `JOB` and `CRON` forbid
   endpoints.
 
-Per the spec, a listing deploys exactly one blueprint, and compute is a
-per-node concern on the blueprint node rather than on the component.
+Per the spec, a `BLUEPRINT` item deploys exactly one blueprint, and compute is a
+per-node concern on the blueprint node rather than on the component. The
+blueprint's `metadata.revision` is the item's revision; a listing carries none.
 
 ## Adding an item
 
@@ -98,7 +101,7 @@ binds compute per node:
 ```yaml
 specVersion: v1
 kind: BLUEPRINT
-metadata: { slug: my-app, revision: 1 }
+metadata: { slug: my-app, revision: 1 }   # the item's revision
 spec:
   components:
     web:                        # graph-local node name (map order = graph order)
@@ -117,9 +120,9 @@ validator could tell which resolver the reference wanted.
 ```yaml
 specVersion: v1
 kind: LISTING
-metadata: { slug: my-app, revision: 1 }
+metadata: { slug: my-app }     # slug only — a listing carries no revision
 spec:
-  listingKind: BLUEPRINT        # BLUEPRINT | COMPONENT
+  itemType: BLUEPRINT           # BLUEPRINT iff the item holds blueprint.yaml
   displayName: My App
   summary: One-line storefront tagline (≤ 280 chars)
   description: |
@@ -127,9 +130,9 @@ spec:
   category: DEVELOPER_TOOLS
   lifecycleStage: STABLE        # STABLE | BETA | EXPERIMENTAL | SUNSET
   tags: [example]
-  homepageUrl: https://example.com
-  sourceRepoUrl: https://github.com/example/my-app
-  license: MIT
+  homepageURL: https://example.com
+  sourceRepoURL: https://github.com/example/my-app
+  license: MIT                  # SPDX expression; LicenseRef-… when SPDX has none
   icon: media/icon.png          # optional; see ICONS.md
   screenshots:                  # optional; {file, caption?} in display order
     - file: media/screenshots/01-home.png
@@ -149,13 +152,14 @@ language-model endpoint — is a component declaring `spec.external` in place of
 `spec.workload`. Its blueprint node writes `size: null`, and the values it holds
 reach the install form through its `USER` inputs like any other node's.
 
-A `COMPONENT`-kind listing that wraps a workload still authors a trivial
-single-node `blueprint.yaml` around its one component, so it can be deployed on
-its own (`postgres`, `redis`). One that publishes an external building block —
-`llm-endpoint` — holds **no** `blueprint.yaml`, as listing spec §3.1 permits: a
-one-node blueprint around a node that runs nothing would deploy nothing. A
-blueprint that needs such a node carries its own copy under `components/`,
-because a repo-local reference cannot leave its item directory.
+An item holding **no** `blueprint.yaml` is an `itemType: COMPONENT` item: a
+single building block rather than a composition — `postgres` and `redis`, which
+wrap a workload, and `llm-endpoint`, which runs nothing. Listing spec §3 binds
+the two together, so a `COMPONENT` item cannot carry a blueprint and a
+`BLUEPRINT` item cannot omit one. Such an item has no item revision; its
+component documents carry their own. A blueprint that needs one of these
+building blocks carries its own copy under `components/`, because a repo-local
+reference cannot leave its item directory.
 
 ## Validation
 
diff --git a/items/code-server/listing.yaml b/items/code-server/listing.yaml
index 9ff54b8..f36cd72 100755
--- a/items/code-server/listing.yaml
+++ b/items/code-server/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: code-server
-  revision: 1
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: code-server
   summary: VS Code in the browser, running on infrastructure you control
   description: |
@@ -36,8 +35,8 @@ spec:
     - vscode
     - editor
     - remote-development
-  homepageUrl: https://coder.com
-  sourceRepoUrl: https://github.com/coder/code-server
-  supportUrl: https://coder.com/docs/code-server
+  homepageURL: https://coder.com
+  sourceRepoURL: https://github.com/coder/code-server
+  supportURL: https://coder.com/docs/code-server
   license: MIT
   icon: media/icon.png
diff --git a/items/flowise/listing.yaml b/items/flowise/listing.yaml
index 4a3a1f9..e113ead 100644
--- a/items/flowise/listing.yaml
+++ b/items/flowise/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: flowise
-  revision: 1
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: Flowise
   summary: Drag-and-drop builder that turns LLM chains and agents into APIs and chat widgets
   description: |
@@ -42,8 +41,8 @@ spec:
     - rag
     - low-code
     - visual-builder
-  homepageUrl: https://flowiseai.com
-  sourceRepoUrl: https://github.com/FlowiseAI/Flowise
-  supportUrl: https://docs.flowiseai.com
+  homepageURL: https://flowiseai.com
+  sourceRepoURL: https://github.com/FlowiseAI/Flowise
+  supportURL: https://docs.flowiseai.com
   license: Apache-2.0
   icon: media/icon.png
diff --git a/items/label-studio/listing.yaml b/items/label-studio/listing.yaml
index 777a0ef..85da86a 100755
--- a/items/label-studio/listing.yaml
+++ b/items/label-studio/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: label-studio
-  revision: 2
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: Label Studio
   summary: Open-source data labeling for text, image, audio, video, and time-series datasets
   description: |
@@ -44,8 +43,8 @@ spec:
     - annotation
     - training-data
     - ml
-  homepageUrl: https://labelstud.io
-  sourceRepoUrl: https://github.com/HumanSignal/label-studio
-  supportUrl: https://labelstud.io/guide
+  homepageURL: https://labelstud.io
+  sourceRepoURL: https://github.com/HumanSignal/label-studio
+  supportURL: https://labelstud.io/guide
   license: Apache-2.0
   icon: media/icon.png
diff --git a/items/langflow/listing.yaml b/items/langflow/listing.yaml
index 81b020a..97aeb7e 100755
--- a/items/langflow/listing.yaml
+++ b/items/langflow/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: langflow
-  revision: 1
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: Langflow
   summary: Visual canvas for prototyping LLM agents and RAG pipelines, exportable as APIs
   description: |
@@ -43,8 +42,8 @@ spec:
     - rag
     - low-code
     - visual-builder
-  homepageUrl: https://www.langflow.org
-  sourceRepoUrl: https://github.com/langflow-ai/langflow
-  supportUrl: https://docs.langflow.org
+  homepageURL: https://www.langflow.org
+  sourceRepoURL: https://github.com/langflow-ai/langflow
+  supportURL: https://docs.langflow.org
   license: MIT
   icon: media/icon.png
diff --git a/items/litellm/listing.yaml b/items/litellm/listing.yaml
index f71c316..6a1a747 100755
--- a/items/litellm/listing.yaml
+++ b/items/litellm/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: litellm
-  revision: 1
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: LiteLLM
   summary: OpenAI-compatible proxy that fronts 100+ LLM providers with keys, budgets, and logging
   description: |
@@ -41,8 +40,8 @@ spec:
     - proxy
     - gateway
     - openai-compatible
-  homepageUrl: https://www.litellm.ai
-  sourceRepoUrl: https://github.com/BerriAI/litellm
-  supportUrl: https://docs.litellm.ai
+  homepageURL: https://www.litellm.ai
+  sourceRepoURL: https://github.com/BerriAI/litellm
+  supportURL: https://docs.litellm.ai
   license: MIT
   icon: media/icon.png
diff --git a/items/llm-endpoint/listing.yaml b/items/llm-endpoint/listing.yaml
index f1df30d..35316a9 100644
--- a/items/llm-endpoint/listing.yaml
+++ b/items/llm-endpoint/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: llm-endpoint
-  revision: 1
 spec:
-  listingKind: COMPONENT
+  itemType: COMPONENT
   displayName: LLM Endpoint
   summary: >-
     A language-model API you already have, as a building block other items can
diff --git a/items/meilisearch/listing.yaml b/items/meilisearch/listing.yaml
index a0125bc..6765756 100755
--- a/items/meilisearch/listing.yaml
+++ b/items/meilisearch/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: meilisearch
-  revision: 1
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: Meilisearch
   summary: Millisecond full-text search engine with typo tolerance, facets, and filters
   description: |
@@ -37,8 +36,8 @@ spec:
     - full-text
     - indexing
     - typo-tolerance
-  homepageUrl: https://www.meilisearch.com
-  sourceRepoUrl: https://github.com/meilisearch/meilisearch
-  supportUrl: https://www.meilisearch.com/docs
+  homepageURL: https://www.meilisearch.com
+  sourceRepoURL: https://github.com/meilisearch/meilisearch
+  supportURL: https://www.meilisearch.com/docs
   license: MIT
   icon: media/icon.png
diff --git a/items/mlflow/listing.yaml b/items/mlflow/listing.yaml
index 40efca8..64ad519 100644
--- a/items/mlflow/listing.yaml
+++ b/items/mlflow/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: mlflow
-  revision: 2
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: MLflow
   summary: Experiment tracking and model registry for ML teams — runs, metrics, artifacts
   description: |
@@ -39,8 +38,8 @@ spec:
     - mlops
     - experiment-tracking
     - model-registry
-  homepageUrl: https://mlflow.org
-  sourceRepoUrl: https://github.com/mlflow/mlflow
-  supportUrl: https://mlflow.org/docs
+  homepageURL: https://mlflow.org
+  sourceRepoURL: https://github.com/mlflow/mlflow
+  supportURL: https://mlflow.org/docs
   license: Apache-2.0
   icon: media/icon.png
diff --git a/items/n8n/listing.yaml b/items/n8n/listing.yaml
index 17f43a0..25f4cbe 100644
--- a/items/n8n/listing.yaml
+++ b/items/n8n/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: n8n
-  revision: 1
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: n8n
   summary: Fair-code workflow automation with 400+ integrations and a built-in code node
   description: |
@@ -39,8 +38,8 @@ spec:
     - workflow
     - integration
     - low-code
-  homepageUrl: https://n8n.io
-  sourceRepoUrl: https://github.com/n8n-io/n8n
-  supportUrl: https://docs.n8n.io
-  license: Sustainable Use License
+  homepageURL: https://n8n.io
+  sourceRepoURL: https://github.com/n8n-io/n8n
+  supportURL: https://docs.n8n.io
+  license: SUL-1.0
   icon: media/icon.png
diff --git a/items/open-webui/listing.yaml b/items/open-webui/listing.yaml
index 50d83af..f9bfe78 100644
--- a/items/open-webui/listing.yaml
+++ b/items/open-webui/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: open-webui
-  revision: 2
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: Open WebUI
   summary: Self-hosted, multi-user chat interface for any OpenAI-compatible language-model API
   description: |
@@ -52,8 +51,8 @@ spec:
     - chat
     - openai-compatible
     - rag
-  homepageUrl: https://openwebui.com
-  sourceRepoUrl: https://github.com/open-webui/open-webui
-  supportUrl: https://docs.openwebui.com
-  license: Open WebUI License (BSD-3-Clause with branding clause)
+  homepageURL: https://openwebui.com
+  sourceRepoURL: https://github.com/open-webui/open-webui
+  supportURL: https://docs.openwebui.com
+  license: LicenseRef-Open-WebUI
   icon: media/icon.png
diff --git a/items/openclaw/listing.yaml b/items/openclaw/listing.yaml
index 2226b0e..7fb9455 100755
--- a/items/openclaw/listing.yaml
+++ b/items/openclaw/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: openclaw
-  revision: 1
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: OpenClaw
   summary: Self-hosted AI agent gateway with a browser Control UI, bring-your-own model keys
   description: |
@@ -63,8 +62,8 @@ spec:
     - assistant
     - gateway
     - automation
-  homepageUrl: https://openclaw.ai
-  sourceRepoUrl: https://github.com/openclaw/openclaw
-  supportUrl: https://docs.openclaw.ai
+  homepageURL: https://openclaw.ai
+  sourceRepoURL: https://github.com/openclaw/openclaw
+  supportURL: https://docs.openclaw.ai
   license: MIT
   icon: media/icon.png
diff --git a/items/postgres/blueprint.yaml b/items/postgres/blueprint.yaml
deleted file mode 100644
index 413606b..0000000
--- a/items/postgres/blueprint.yaml
+++ /dev/null
@@ -1,12 +0,0 @@
-specVersion: v1
-kind: BLUEPRINT
-metadata:
-  slug: postgres
-  revision: 2
-spec:
-  components:
-    db:
-      componentRef: ./components/postgres.yaml
-      size: general.standard.small
-      connections: {}
-  parameters: {}
diff --git a/items/postgres/listing.yaml b/items/postgres/listing.yaml
index 448b64b..bd41d1b 100644
--- a/items/postgres/listing.yaml
+++ b/items/postgres/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: postgres
-  revision: 2
 spec:
-  listingKind: COMPONENT
+  itemType: COMPONENT
   displayName: PostgreSQL
   summary: The open-source relational database — SQL, ACID transactions, and JSONB in one engine
   description: |
@@ -37,7 +36,7 @@ spec:
     - sql
     - postgres
     - relational
-  homepageUrl: https://www.postgresql.org
-  sourceRepoUrl: https://github.com/postgres/postgres
+  homepageURL: https://www.postgresql.org
+  sourceRepoURL: https://github.com/postgres/postgres
   license: PostgreSQL
   icon: media/icon.png
diff --git a/items/qdrant/listing.yaml b/items/qdrant/listing.yaml
index b015311..53f22f3 100755
--- a/items/qdrant/listing.yaml
+++ b/items/qdrant/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: qdrant
-  revision: 2
 spec:
-  listingKind: BLUEPRINT
+  itemType: BLUEPRINT
   displayName: Qdrant
   summary: Rust vector database for similarity search and RAG retrieval on CPU hardware
   description: |
@@ -46,8 +45,8 @@ spec:
     - similarity-search
     - rag
     - ai
-  homepageUrl: https://qdrant.tech
-  sourceRepoUrl: https://github.com/qdrant/qdrant
-  supportUrl: https://qdrant.tech/documentation
+  homepageURL: https://qdrant.tech
+  sourceRepoURL: https://github.com/qdrant/qdrant
+  supportURL: https://qdrant.tech/documentation
   license: Apache-2.0
   icon: media/icon.png
diff --git a/items/redis/blueprint.yaml b/items/redis/blueprint.yaml
deleted file mode 100644
index 6c709f2..0000000
--- a/items/redis/blueprint.yaml
+++ /dev/null
@@ -1,12 +0,0 @@
-specVersion: v1
-kind: BLUEPRINT
-metadata:
-  slug: redis
-  revision: 1
-spec:
-  components:
-    cache:
-      componentRef: ./components/redis.yaml
-      size: general.standard.small
-      connections: {}
-  parameters: {}
diff --git a/items/redis/listing.yaml b/items/redis/listing.yaml
index 2507771..d89adfa 100644
--- a/items/redis/listing.yaml
+++ b/items/redis/listing.yaml
@@ -2,9 +2,8 @@ specVersion: v1
 kind: LISTING
 metadata:
   slug: redis
-  revision: 1
 spec:
-  listingKind: COMPONENT
+  itemType: COMPONENT
   displayName: Redis
   summary: In-memory data store for caching, queues, sessions, and pub/sub
   description: |
@@ -35,7 +34,7 @@ spec:
     - key-value
     - redis
     - message-broker
-  homepageUrl: https://redis.io
-  sourceRepoUrl: https://github.com/redis/redis
-  license: RSALv2 / SSPLv1 / AGPL-3.0
+  homepageURL: https://redis.io
+  sourceRepoURL: https://github.com/redis/redis
+  license: LicenseRef-RSALv2 OR SSPL-1.0 OR AGPL-3.0-only
   icon: media/icon.png
diff --git a/tests/README.md b/tests/README.md
index d2b9f02..f21672a 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -53,7 +53,7 @@ phases pass.
 | `spec.test.ts` | — | The bundles resolve, name their own family, and are self-contained. Fails first, so a corpus is never judged against a 404 page. |
 | `parser.test.ts` | `parser` | Every document satisfies the Musher YAML profile (core §6.1): one document per file, string keys, no anchors, aliases, merge keys or explicit tags, and the size, depth and scalar bounds. |
 | `structural.test.ts` | `structural` | Every document validates against its family's fetched JSON Schema. |
-| `semantic.test.ts` | `semantic` | The cross-document rules: identity agreement, reference resolution, path containment, media, the description Markdown profile, image pinning, endpoint resolution, `INPUT` output references (COMP-OUT-002/003), node compute against external components (BP-NODE-002), connection compatibility including which inputs a wire may fill (BP-CONN-001), and parameter coverage and agreement. |
+| `semantic.test.ts` | `semantic` | The cross-document rules: identity agreement, the listing's `itemType` against the item root (LIST-ITEM-001), reference resolution, path containment, media, the description Markdown profile, image pinning, endpoint resolution, `INPUT` output references (COMP-OUT-002/003), node compute against external components (BP-NODE-002), connection compatibility including which inputs a wire may fill (BP-CONN-001), and parameter coverage and agreement. |
 | `layout.test.ts` | — | The item folder structure, and the catalog's own additions to it. |
 | `rules.test.ts` | — | The rules themselves, against deliberately broken synthetic items. |
 
diff --git a/tests/layout.test.ts b/tests/layout.test.ts
index e5cf7bf..1873f80 100644
--- a/tests/layout.test.ts
+++ b/tests/layout.test.ts
@@ -7,6 +7,9 @@
  * `blueprint.yaml`, `listing.yaml`, and `media/` — so this file tests those and
  * the catalog's own additions on top of them, which the repository README states
  * as hard requirements for a platform sync.
+ *
+ * Which items hold a blueprint is not tested here. LIST-ITEM-001 binds it to
+ * the listing's `itemType` in both directions, so the semantic phase decides it.
  */
 import fs from 'node:fs';
 import path from 'node:path';
@@ -20,7 +23,6 @@ import {
   MEDIA_DIR,
   SLUG_PATTERN,
   discoverItems,
-  loadItemDocuments,
 } from './lib/catalog.ts';
 import { ITEMS_DIR, rel } from './lib/paths.ts';
 
@@ -65,23 +67,6 @@ for (const item of items) {
       assert.ok(item.listingPath, `${rel(item.root)} holds no ${LISTING_FILE}`);
     });
 
-    it(`holds ${BLUEPRINT_FILE}, unless it is a COMPONENT item`, async () => {
-      // Listing spec §3.1 lets a COMPONENT-kind item ship with no blueprint, and
-      // this corpus narrows that to a catalog rule: a BLUEPRINT item must hold
-      // one. A COMPONENT item wrapping a workload still authors a trivial
-      // single-node blueprint so it is deployable on its own (postgres, redis).
-      // An external building block does not, because a one-node blueprint around
-      // a node that runs nothing would deploy nothing.
-      if (item.blueprintPath) return;
-      const { listing } = await loadItemDocuments(item);
-      const listingKind = (listing?.value?.['spec'] as Record<string, unknown> | undefined)?.['listingKind'];
-      assert.equal(
-        listingKind,
-        'COMPONENT',
-        `${rel(item.root)} holds no ${BLUEPRINT_FILE}, and only a listingKind: COMPONENT item may omit one`,
-      );
-    });
-
     it('holds at least one component document', () => {
       assert.ok(item.componentPaths.length > 0, `${rel(item.root)} holds no component document`);
     });
diff --git a/tests/lib/semantic.ts b/tests/lib/semantic.ts
index 1dac0d9..d8c1122 100644
--- a/tests/lib/semantic.ts
+++ b/tests/lib/semantic.ts
@@ -129,7 +129,7 @@ export function buildContext(
 
 /* ---------------------------------------------------------------- identity */
 
-/** CORE-ITEM-001, CORE-ITEM-002. */
+/** CORE-ITEM-001. */
 export function checkIdentity(context: SemanticContext): Diagnostic[] {
   const { item, documents } = context;
   const found: Diagnostic[] = [];
@@ -151,25 +151,38 @@ export function checkIdentity(context: SemanticContext): Diagnostic[] {
     }
   }
 
-  // The rule takes two operands. A COMPONENT item holding no blueprint has no
-  // second one — not a different one — so it goes silent rather than failing.
-  // The field is `revision` and the code is still ERR_VERSION_MISMATCH: ADR 0007
-  // §3 renamed the field and left the diagnostic, which core spec §7's table keeps.
-  const listingRevision = metadataOf(documents.listing)['revision'];
-  const blueprintRevision = metadataOf(documents.blueprint)['revision'];
-  if (documents.listing?.value && documents.blueprint?.value && listingRevision !== blueprintRevision) {
-    found.push(
-      diag(
-        'ERR_VERSION_MISMATCH',
-        `${documents.blueprint.label} /metadata/revision`,
-        `blueprint revision ${JSON.stringify(blueprintRevision)} disagrees with listing revision ${JSON.stringify(listingRevision)}`,
-      ),
-    );
-  }
-
   return found;
 }
 
+/**
+ * LIST-ITEM-001 — listing spec §3. `spec.itemType` is `BLUEPRINT` if and only if
+ * the item root holds `blueprint.yaml`.
+ *
+ * It reads the directory rather than the document, which is what makes it
+ * `semantic`. Holding the file is what counts, not whether it parses: a broken
+ * blueprint is still a blueprint, and the parser phase reports it.
+ */
+export function checkItemType(context: SemanticContext): Diagnostic[] {
+  const listing = context.documents.listing;
+  if (!listing?.value) return [];
+
+  const declared = specOf(listing)['itemType'];
+  if (typeof declared !== 'string') return [];
+
+  const holdsBlueprint = context.item.blueprintPath !== null;
+  if (declared === (holdsBlueprint ? 'BLUEPRINT' : 'COMPONENT')) return [];
+
+  return [
+    diag(
+      'ERR_ITEM_TYPE_MISMATCH',
+      `${listing.label} /spec/itemType`,
+      holdsBlueprint
+        ? `itemType is ${declared}, but the item root holds a blueprint.yaml`
+        : `itemType is ${declared}, but the item root holds no blueprint.yaml`,
+    ),
+  ];
+}
+
 /* -------------------------------------------------------------- references */
 
 /** Blueprint spec §4.1 and BP-ID-003. */
diff --git a/tests/rules.test.ts b/tests/rules.test.ts
index 65ad588..7dc7cae 100644
--- a/tests/rules.test.ts
+++ b/tests/rules.test.ts
@@ -28,6 +28,7 @@ import {
   checkHealthProbes,
   checkIdentity,
   checkImagePinning,
+  checkItemType,
   checkMedia,
   checkNodeCompute,
   checkOutputInputReferences,
@@ -48,9 +49,9 @@ type Doc = Record<string, unknown>;
 const listing = (over: Doc = {}): Doc => ({
   specVersion: 'v1',
   kind: 'LISTING',
-  metadata: { slug: 'acme-wiki', revision: 1 },
+  metadata: { slug: 'acme-wiki' },
   spec: {
-    listingKind: 'BLUEPRINT',
+    itemType: 'BLUEPRINT',
     displayName: 'Acme Wiki',
     summary: 'A wiki',
     description: 'Long-form copy.',
@@ -155,6 +156,7 @@ async function diagnose(root: string): Promise<Diagnostic[]> {
 
   return [
     ...checkIdentity(context),
+    ...checkItemType(context),
     ...checkComponentReferences(context),
     ...checkMedia(context),
     ...checkDescription(context),
@@ -224,9 +226,27 @@ describe('identity — blueprint §3, listing §3', () => {
   it('ERR_SLUG_MISMATCH when metadata.slug disagrees with the directory name', async () => {
     await assertReports({ blueprint: blueprint({ metadata: { slug: 'other', revision: 1 } }) }, 'ERR_SLUG_MISMATCH');
   });
+});
+
+describe('item type — listing §3, LIST-ITEM-001', () => {
+  const componentItem = { blueprint: null, listing: listing({ spec: { itemType: 'COMPONENT' } }) };
+
+  it('ERR_ITEM_TYPE_MISMATCH when a BLUEPRINT listing sits in an item holding no blueprint', async () => {
+    // spec listing conformance semantic/015: a composition nobody can install.
+    await assertReports({ blueprint: null }, 'ERR_ITEM_TYPE_MISMATCH');
+  });
+
+  it('ERR_ITEM_TYPE_MISMATCH when a COMPONENT listing sits beside a blueprint', async () => {
+    // spec listing conformance semantic/016.
+    await assertReports({ listing: listing({ spec: { itemType: 'COMPONENT' } }) }, 'ERR_ITEM_TYPE_MISMATCH');
+  });
+
+  it('accepts a COMPONENT item holding no blueprint', async () => {
+    await assertClean(componentItem);
+  });
 
-  it('ERR_VERSION_MISMATCH when the two halves of the item disagree', async () => {
-    await assertReports({ blueprint: blueprint({ metadata: { slug: 'acme-wiki', revision: 2 } }) }, 'ERR_VERSION_MISMATCH');
+  it('the accepted COMPONENT item is a real item', async () => {
+    await assertStructurallyValid(build(componentItem));
   });
 });
 
diff --git a/tests/semantic.test.ts b/tests/semantic.test.ts
index 9ba06a6..0042bf1 100644
--- a/tests/semantic.test.ts
+++ b/tests/semantic.test.ts
@@ -26,6 +26,7 @@ import {
   checkHealthProbes,
   checkIdentity,
   checkImagePinning,
+  checkItemType,
   checkMedia,
   checkNodeCompute,
   checkOutputInputReferences,
@@ -66,11 +67,16 @@ const report = (diagnostics: Diagnostic[]): string[] =>
 
 for (const item of items) {
   describe(`items/${item.slug}`, () => {
-    it('slug and version agree across the item — CORE-ITEM-001/002', async () => {
+    it('slug agrees with the item directory — CORE-ITEM-001', async () => {
       const { context } = await contextFor(item);
       assert.deepEqual(report(checkIdentity(context)), []);
     });
 
+    it('itemType agrees with what the item root holds — LIST-ITEM-001', async () => {
+      const { context } = await contextFor(item);
+      assert.deepEqual(report(checkItemType(context)), []);
+    });
+
     it('every component reference resolves to a document inside the item root — §4.1, BP-ID-003', async () => {
       const { context } = await contextFor(item);
       assert.deepEqual(report(checkComponentReferences(context)), []);
diff --git a/tests/structural.test.ts b/tests/structural.test.ts
index cdf4d7a..fc9c9ba 100644
--- a/tests/structural.test.ts
+++ b/tests/structural.test.ts
@@ -40,13 +40,13 @@ for (const item of items) {
     });
 
     it('blueprint.yaml validates against the blueprint schema', async (t) => {
-      const { blueprint, listing } = await loadItemDocuments(item);
-      if (!blueprint && (listing?.value?.['spec'] as Record<string, unknown> | undefined)?.['listingKind'] === 'COMPONENT') {
-        // Listing spec §3.1: a COMPONENT item may hold no blueprint. Whether
-        // this one may is layout.test.ts's question, not this phase's.
-        t.skip('a COMPONENT item holding no blueprint');
+      if (!item.blueprintPath) {
+        // Listing spec §3.1: an item may hold no blueprint. Whether this one
+        // may is LIST-ITEM-001's question, which the semantic phase answers.
+        t.skip('an item holding no blueprint');
         return;
       }
+      const { blueprint } = await loadItemDocuments(item);
       assert.ok(blueprint, `items/${item.slug} holds no blueprint.yaml`);
       await assertValidates('blueprint', blueprint);
     });