Amazon Lex announces support for Alphanumeric slot type
Amazon Lex now supports Alphanumeric slot type allowing you to easily define slots such as flight confirmation code that contain combination of letters and numbers. Up until now, you had to create a custom slot type with a large range of sample values. By using the Alphanumeric slot type you can quickly set up a slot to capture alphanumeric information. Further, you can extend this slot type to restrict the user input to a fixed format by specifying a regular expression.
Source:: Amazon AWS