INSURANCE PERIODS;
3 . REGULATIONS NOS 3 AND 4 AND IN PARTICULAR ARTICLES 27 AND 28 OF REGULATION NO 3 TOGETHER WITH ARTICLES 30 TO 36 AND 83 OF REGULATION NO 4 DO NOT IMPLY THAT THERE IS AN OBLIGATION TO DETERMINE SIMULTANEOUSLY AND ON THE BASIS OF THE SAME REFERENCE DATE AN OLD-AGE PENSION ACQUIRED IN ONE MEMBER STATE UNDER ARTICLE 27 AND ANOTHER OLD-AGE PENSION WHICH HAS NOT YET BEEN ACQUIRED IN ANOTHER MEMBER STATE OR WHICH HAS BEEN ACQUIRED IN ANOTHER MEMBER STATE WHOSE LEGISLATION PERMITS ITS PAYMENT TO BE DEFERRED AT THE REQUEST OF THE PERSON CONCERNED;
4 . CLAIMING A PENSION FROM A SOCIAL SECURITY INSTITUTION OF ONE MEMBER STATE DOES NOT IMPLY A WAIVER OF THE RIGHTS OF ELECTION WHICH THE LEGISLATIVE SYSTEMS OF OTHER MEMBER STATES GRANT TO THE WORKERS CONCERNED . THE NATIONAL SOCIAL SECURITY AUTHORITIES ARE COMPETENT TO DECIDE WHEN SUCH ELECTION MUST BE MADE;
5 . THE DECISION AS TO COSTS IN THESE PROCEEDINGS IS A MATTER FOR THE BELGIAN CONSEIL D' ETAT .