Hi George, thanks for this feedback, that's much appreciated.

One issue I see with @ParameterTuple is that you can't define it in a generic way (you can't define an annotation member Annotation value(), you always need to specify a concrete annotation type). So we'd need a @ParameterTuple annotation for each constraint.

One could think about adding an attribute to constraint annotations which expresses the target:

@EqualPasswords(applysToParameters=true)
public void register(String username, String password, String confirmPassword) {

}

What I like about your proposal is that it probably would make some things in the spec easier regarding wording etc.

Emmanuel Bernard: WDYT?