diff --git a/includes/Api/OrdersController.php b/includes/Api/OrdersController.php
index 437ab98..9df31bf 100644
--- a/includes/Api/OrdersController.php
+++ b/includes/Api/OrdersController.php
@@ -2216,20 +2216,8 @@ class OrdersController {
       }
       
       // Private meta (starts with _) - check if allowed
-      $allowed_private = apply_filters( 'woonoow/order_allowed_private_meta', [
-        // Common shipping tracking fields
-        '_tracking_number',
-        '_tracking_provider',
-        '_tracking_url',
-        '_shipment_tracking_items',
-        '_wc_shipment_tracking_items',
-        
-        // Payment gateway meta
-        '_transaction_id',
-        '_payment_method_title',
-        
-        // Allow plugins to add their meta via filter
-      ], $order );
+      // Core has ZERO defaults - plugins register via filter
+      $allowed_private = apply_filters( 'woonoow/order_allowed_private_meta', [], $order );
       
       if ( in_array( $key, $allowed_private, true ) ) {
         $meta_data[ $key ] = $value;
@@ -2247,14 +2235,8 @@ class OrdersController {
    */
   private static function update_order_meta_data( $order, $meta_updates ) {
     // Get allowed updatable meta keys
-    $allowed = apply_filters( 'woonoow/order_updatable_meta', [
-      // Common shipping tracking fields
-      '_tracking_number',
-      '_tracking_provider',
-      '_tracking_url',
-      
-      // Allow plugins to add their meta via filter
-    ], $order );
+    // Core has ZERO defaults - plugins register via filter
+    $allowed = apply_filters( 'woonoow/order_updatable_meta', [], $order );
     
     foreach ( $meta_updates as $key => $value ) {
       // Skip internal WooCommerce meta
diff --git a/includes/Api/ProductsController.php b/includes/Api/ProductsController.php
index 86b80ee..6c15f5d 100644
--- a/includes/Api/ProductsController.php
+++ b/includes/Api/ProductsController.php
@@ -743,12 +743,8 @@ class ProductsController {
 			}
 			
 			// Private meta (starts with _) - check if allowed
-			$allowed_private = apply_filters('woonoow/product_allowed_private_meta', [
-				// Common custom fields
-				'_custom_field',
-				
-				// Allow plugins to add their meta via filter
-			], $product);
+			// Core has ZERO defaults - plugins register via filter
+			$allowed_private = apply_filters('woonoow/product_allowed_private_meta', [], $product);
 			
 			if (in_array($key, $allowed_private, true)) {
 				$meta_data[$key] = $value;
@@ -766,12 +762,8 @@ class ProductsController {
 	 */
 	private static function update_product_meta_data($product, $meta_updates) {
 		// Get allowed updatable meta keys
-		$allowed = apply_filters('woonoow/product_updatable_meta', [
-			// Common custom fields
-			'_custom_field',
-			
-			// Allow plugins to add their meta via filter
-		], $product);
+		// Core has ZERO defaults - plugins register via filter
+		$allowed = apply_filters('woonoow/product_updatable_meta', [], $product);
 		
 		foreach ($meta_updates as $key => $value) {
 			// Skip internal WooCommerce meta