Which of the following is not a validation incorporated into OutSystems?

The notion that maximum length of text fields is not a validation incorporated into OutSystems is not accurate. In OutSystems, validations play a crucial role in ensuring data integrity and enhancing user experience. Each of the aspects listed in the question is indeed a standard validation feature within the platform.

Required fields ensure that users do not submit forms with missing essential information, promoting the completeness of data entries. Input field data types verify that the input corresponds to expected formats, such as numbers, dates, or strings, thereby reducing errors during data processing. Custom error messages allow developers to provide user-friendly feedback if validations fail, ensuring that users understand what corrections are needed.

On the other hand, while it is true that maximum length validation might not be as prominently addressed as other validations such as required fields, it is indeed implemented as a property of text fields in the platform. Thus, the concept of maximum length validation is part of the broader validation framework OutSystems provides. Understanding these validations is crucial for building robust applications that effectively manage user inputs and maintain data quality.