An RDS event notifications subscription should be configured for critical database parameter group events

NIST

Description

Verifies that an RDS event subscription is configured for critical database parameter group events.

Configure an RDS event subscription for 'db-parameter-group' source type with 'configuration change' event.

Log in to the AWS Management Console and open the Amazon RDS console.
Go to 'Event subscriptions'.
Create or modify an event subscription.
Set source type to 'DB parameter group' and include 'configuration change' events.
Save the subscription.

NIST