/resources/customer_negative_criterion.proto 

--- v20/resources/customer_negative_criterion.proto 2025-08-05 14:39:35.000000000 +0000
+++ v21/resources/customer_negative_criterion.proto 2025-08-05 14:39:50.000000000 +0000
@@ -86,11 +86,15 @@
         [(google.api.field_behavior) = IMMUTABLE];

     // Immutable. NegativeKeywordList.
-    google.ads.googleads.v20.common.NegativeKeywordListInfo
+    google.ads.googleads.v21.common.NegativeKeywordListInfo
         negative_keyword_list = 11 [(google.api.field_behavior) = IMMUTABLE];

     // Immutable. IPBLock
-    google.ads.googleads.v20.common.IpBlockInfo ip_block = 12
+    google.ads.googleads.v21.common.IpBlockInfo ip_block = 12
+        [(google.api.field_behavior) = IMMUTABLE];
+
+    // Immutable. PlacementList.
+    google.ads.googleads.v21.common.PlacementListInfo placement_list = 13
         [(google.api.field_behavior) = IMMUTABLE];
   }
 }