Today, AWS CloudFormation updates the language extension transform to support default values and additional intrinsic functions in Fn::FindInMap. Customers can use these features to minimize the size of their CloudFormation templates, and improve their readability. The language transform extends CloudFormation template language with functions such as Fn::Length, Fn::JsonToString, and more. Customers can modularize their templates into groups with different attributes in Parameters and Mappings, and use Fn::FindInMap to refer to attributes of these groups. For example, you can use Fn::FindInMap for EC2 resource type with a Mappings section containing a single map, RegionMap, that associates AMIs with AWS Regions to your EC2 instances. With these language enhancements, you can use intrinsic functions such as Fn::Split, Fn::Select, and others within Fn::FindInMap. Previously, Fn::FindInMap only supported Ref intrinsic functions. Additionally, you can define string or list type default values in Fn::FindInMap. To see the list of supported intrinsic functions and learn about Fn:FindInMap, refer to the user guide.
Source:: Amazon AWS