AWS::RDS::EventSubscription:

Properties:
  Enabled: "true"
  EventCategories: |
    [
     "restoration", 
     "maintenance", 
     "recovery",
     "backup",
     "notification",
     "availability",
     "failure",
     "deletion",
     "creation",
     "low storage",
     "configuration change",
     "failover",
     "read replica",
     "failure",
     "configuration change",
     "configuration change",
     "deletion",
     "restoration",
     "creation",
     "notification",
     "failure",
     "failover",
     "notification",
     "backup" 
    ]
  SnsTopicArn: "\"topic-arn\""
  SourceIds: |
    [ 
      "instance-id-a", 
      "instance-id-b", 
      "you can leave this blank, so it subscribe to all resources" 
    ]
  SourceType: |
    "db-instance|db-security-group|db-parameter-group|db-snapshot|db-cluster|db-cluster-snapshot"