Spring provides an object validation framework that leverages the functionality provided in the Expressions namespace. (See Chapter 7, Expression Evaluation for more information). The validation framework is in Spring.Core assembly under the namespace Spring.Validation. We apologize that reference documentation for this functionality is not yet available. You can currently get some information on this functionality by looking at the SDK documentation and also by running the SpringAir sample application provided in the nightly builds. Please post to the Spring.NET forums with any questions.