Domain Definition validations implemented in the client infrastructure include a custom validation type which corresponds to a developer-supplied function for performing validations on data entered by users via the client interface.
This option allows the developer to specify the name of this function which associates it with the application UML model. The value of the option should be simply the name of a function (just function, not class + function, since the class name is defaulted in the client code). It must also be a valid Java identifier.