diff --git a/cloudtrail-key/main.tf b/cloudtrail-key/main.tf
index 65e1e12..518a947 100644
--- a/cloudtrail-key/main.tf
+++ b/cloudtrail-key/main.tf
@@ -312,3 +312,6 @@ data "aws_iam_policy_document" "key" {
     }
   }
 }
+
+# producers and consumers
+#  https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-key-management.html#compatibility-with-aws-services