Currently method parameter constraints are denoted using @CrossParameterConstraint when a constraint is defined.

I propose that method parameter constraints are "normal" constraints and the application to method parameters is denoted when the constraint is declared on a method:

@ParameterTuple(@EqualPasswords)
public void register(String username, String password, String confirmPassword) {

}

I also propose a name more based on programming language terms (e.g. @ParameterTuple) than usage terms (@CrossParameterConstraint).