Read chapter 10.2 of the documentation(Seam1.2.0.Patch1)
Near the end of this chapter
Right I've missed this fragment. Thanks.
Actually visibility of String getCreatedMessage() method should be set to public and not to protected (as in doc). And then the only need is to return proper key from ResourceBundle regarding type of person to be saved i.e. student, teacher.
Locale is determined automagically :)