AWS CloudFormation launches a new deletion policy called RetainExceptOnCreate that provides customers additional control over CloudFormation behavior when resources are deleted from stacks. Customers use deletion policies to preserve or backup resources during accidental stack deletions. Today, customers can mark resources with a deletion policy of Retain, Snapshot, or Delete. Now, customers can use RetainExceptOnCreate to protect in-use resources from accidental deletion without preserving resources that have not served traffic. This allows customers to reduce manual intervention during retries of stack operations.
Source:: Amazon AWS