TAKEN IN IMPLEMENTATION OF THEM MUST THEREFORE BE CONSTRUED SO AS TO AVOID PLACING MIGRANT WORKERS IN AN UNFAVOURABLE LEGAL POSITION, PARTICULARLY WITH REGARD TO SOCIAL SECURITY . ON THE OTHER HAND THESE PROVISIONS ARE NOT OPPOSED TO LEGISLATION BY THE MEMBER STATES DESIGNED TO BRING ABOUT ADDITIONAL PROTECTION BY WAY OF SOCIAL SECURITY FOR THE BENEFIT OF MIGRANT WORKERS .
IF A PROHIBITION OF THE SIMULTANEOUS APPLICATION OF TWO NATIONAL SYSTEMS OF LEGISLATION CONCERNING WORKERS CANNOT BE ESTABLISHED IN THE ABSENCE OF A SPECIFIC PROVISION FOR THAT PURPOSE, THERE IS ALL THE MORE REASON WHY THIS SHOULD BE SO WHEN ONE OF THE SYSTEMS, FAR FROM BEING INTENDED ONLY FOR WORKERS, APPLIES WITHOUT DISTINCTION TO THE WHOLE POPULATION BY VIRTUE OF A CRITERION DEPENDING NOT ON THE EXERCISE OF A WAGE-EARNING ACTIVITY BUT ON RESIDENCE ALONE . ARTICLES 48 TO 51 OF THE TREATY, WHICH ARE INCORPORATED IN THE CHAPTER HEADED ' WORKERS ', AND WHICH CONSTITUTE THE FOUNDATION, THE FRAMEWORK AND THE LIMITS OF REGULATION N . 3, PROVIDE NO AUTHORITY FOR PROHIBITING A STATE FROM GRANTING ADDITIONAL PROTECTION BY WAY OF SOCIAL SECURITY TO ITS WHOLE POPULATION INCLUDING THOSE OF ITS NATIONALS WHO WORK IN ANOTHER MEMBER COUNTRY .
FOR THE FOREGOING REASONS, ARTICLE 12 REGULATION N . 3 DOES NOT PROHIBIT THE APPLICATION OF THE LEGISLATION OF A MEMBER STATE OTHER THAN THAT IN WHICH THE PERSON CONCERNED WORKS, EXCEPT TO THE EXTENT THAT IT REQUIRES THAT PERSON TO CONTRIBUTE TO THE FINANCING OF A SOCIAL SECURITY INSTITUTION WHICH IS UNABLE TO PROVIDE HIM WITH ADDITIONAL ADVANTAGES IN RESPECT OF THE SAME RISK AND OF THE SAME PERIOD .
CONSEQUENTLY IT IS PERMISSIBLE FOR STATES, OTHER THAN THAT IN THE TERRITORY OF WHICH THE INSURED PERSON IS EMPLOYED, TO PROVIDE OR NOT TO PROVIDE FOR THE GRANT OF RIGHTS TO BENEFITS IN FAVOUR OF THAT PERSON EVEN IF HE ENJOYS, IN RESPECT OF THE SAME RISK AND PERIOD, SIMILAR RIGHTS UNDER THE LEGISLATION OF THE STATE IN WHICH HE WORKS .
2 . THE CENTRALE RAAD ASKS THE COURT IN THE SECOND PART OF ITS QUESTION TO SAY WHETHER, TO THE EXTENT THAT ARTICLE 12 EXCLUDES THE APPLICATION OF THE LEGISLATION OF OTHER STATES, THIS RULE IS SUBJECT TO AN EXCEPTION WHEN IN FACT THE PERSON INSURED OR HIS DEPENDANTS CANNOT ASSERT ANY RIGHT ON THE BASIS OF THE LEGISLATION OF THE STATE REFERRED TO IN THE SAID ARTICLE .
IT FOLLOWS FROM THE FOREGOING CONSIDERATIONS THAT ARTICLE 12 DOES NOT PROHIBIT OTHER STATES FROM ALLOWING THOSE CONCERNED A RIGHT TO BENEFITS .
Decision on costs
3 . THE COSTS INCURRED BY THE COMMISSION OF THE EEC WHICH HAS SUBMITTED ITS OBSERVATIONS TO THE COURT ARE NOT RECOVERABLE .
AS THE PROCEEDINGS ARE, SO FAR AS THE PARTIES TO THE MAIN ACTION ARE CONCERNED, IN THE NATURE OF A STEP IN THE ACTION BEFORE THE CENTRALE RAAD VAN BEROEP IT IS FOR THAT COURT TO MAKE A DECISION AS TO COSTS .
Operative part
THE COURT