importExistingResources

Indicates if the change set auto-imports resources that already exist. For more information, see Import Amazon Web Services resources into a CloudFormation stack automatically in the CloudFormation User Guide.

This parameter can only import resources that have custom names in templates. For more information, see name type in the CloudFormation User Guide. To import resources that do not accept custom names, such as EC2 instances, use the ResourcesToImport parameter instead.