Which feature ensures the uniqueness of a semantic key in RESTful Application Programming?

The feature that ensures the uniqueness of a semantic key in RESTful Application Programming is validation. In this context, validation is a critical aspect that ensures the data being processed adheres to defined standards and requirements, particularly when it comes to ensuring that each instance of a semantic key is unique.

When a semantic key is validated, the system checks whether it already exists in the database or data structure before allowing the operation to proceed. This prevents duplication and ensures that each key is associated with its specific resource. Validation involves checking the correctness, completeness, and validity of the data, which is essential for maintaining data integrity within the application.

In contrast, action refers to operations that can be performed on the data, determination involves the process of defining certain characteristics based on input, and service binding pertains to establishing connections between services and applications. While these aspects are also important in the context of RESTful programming, they do not directly address the uniqueness of semantic keys as validation does.