diff --git a/core-spec/spec.md b/core-spec/spec.md
index 8b9c10a..67a4b98 100644
--- a/core-spec/spec.md
+++ b/core-spec/spec.md
@@ -83,7 +83,9 @@ semantic_model:
     description: Sales and customer analytics model
     ai_context:
       instructions: "Use this model for sales analysis and customer insights"
-    datasets: []
+    datasets:
+      - name: orders
+        source: sales.public.orders
     relationships: []
     metrics: []
     custom_extensions:
@@ -337,8 +339,9 @@ expression:
 ```yaml
 - name: total_revenue
   expression:
-    - dialect: ANSI_SQL
-      expression: SUM(orders.amount)
+    dialects:
+      - dialect: ANSI_SQL
+        expression: SUM(orders.amount)
   description: Total revenue across all orders
   ai_context:
     synonyms:
@@ -351,8 +354,9 @@ expression:
 ```yaml
 - name: avg_orders
   expression:
-    - dialect: ANSI_SQL
-      expression: SUM(orders.amount) / COUNT(DISTINCT customers.id)
+    dialects:
+      - dialect: ANSI_SQL
+        expression: SUM(orders.amount) / COUNT(DISTINCT customers.id)
   description: Average orders
   ai_context:
     synonyms:
@@ -445,6 +449,7 @@ The following are well-known examples:
 Here's a complete semantic model example showing all components working together:
 
 ```yaml
+version: 0.2.0.dev0
 semantic_model:
   - name: ecommerce_analytics
     description: E-commerce sales and customer analytics
diff --git a/core-spec/spec.yaml b/core-spec/spec.yaml
index 7229e08..3265e79 100644
--- a/core-spec/spec.yaml
+++ b/core-spec/spec.yaml
@@ -91,11 +91,9 @@ datasets:
     # Can be a single column or a composite of multiple columns
     # This is the preferred unique identifier for this dataset and is used in relationships to determine many-to-one or one-to-one.
     # Examples:
-    # primary_key:
-    #   - [customer_id]           # Simple primary key
+    # primary_key: [customer_id]            # Simple primary key
     #
-    # primary_key:
-    #   - [order_id, line_number] # Composite primary key
+    # primary_key: [order_id, line_number]  # Composite primary key
     primary_key: []  # Array of column names (single or composite)
 
     # Optional: Array of unique key definitions that uniquely identify rows in this dataset