( PRINCIPLE OF THE PROHIBITION ON OVERLAPPING INSURANCE ) - THAT PROVISION , AS HAS JUST BEEN INDICATED , BEING UNDERSTOOD AND IMPLEMENTED BY THE COMPETENT INSTITUTIONS AS REFERRING ONLY TO PERIODS OF CONTRIBUTION TO INSURANCE IN THE FEDERAL REPUBLIC OF GERMANY - AND ,
( C ) BUYING-IN MUST START WITH THE MOST RECENT MISSING PERIODS AND GO PROGRESSIVELY FURTHER BACK IN THE PAST ( PRINCIPLE OF RETROGRESSIVE BUYING-IN ).
10 FOLLOWING THE INTERVENTION OF THE COMMISSION THE FEDERAL REPUBLIC OF GERMANY ACCEPTED THAT THE BENEFIT OF THAT PROVISION SHOULD BE EXTENDED TO THE NATIONALS OF OTHER MEMBER STATES WHO DID NOT RESIDE IN THE FEDERAL REPUBLIC OF GERMANY PROVIDED THAT THEY HAD PREVIOUSLY BEEN COMPULSORILY OR VOLUNTARILY INSURED UNDER THE GERMAN OLD-AGE PENSION INSURANCE SCHEME . THAT IS THE OBJECT OF PARAGRAPHS 8 AND 9 OF PART C OF ANNEX V , AMENDED TO THAT END IN 1974 .
11 THOSE TWO PROVISIONS ARE CLOSELY LINKED AND MUST BE CONSTRUED IN CONJUNCTION WITH ONE ANOTHER . THEY DISTINGUISH BETWEEN , ON THE ONE HAND , WORKERS WHO DERIVE THEIR RIGHT TO AVAIL THEMSELVES OF ARTICLE 49A ( 2 ) DIRECTLY FROM THE GERMAN LEGISLATION , NAMELY GERMAN NATIONALS WHATEVER THEIR PLACE OF RESIDENCE AND NATIONALS OF OTHER MEMBER STATES RESIDING IN THE FEDERAL REPUBLIC OF GERMANY WHO ARE REFERRED TO IN PARAGRAPH 8 ( A ) AND IN THE FIRST SENTENCE OF PARAGRAPH 9 , AND , ON THE OTHER HAND , WORKERS ENTITLED TO APPLY TO ' ' BUY-IN ' ' ONLY BY VIRTUE OF COMMUNITY LAW , WHO ARE REFERRED TO IN PARA- GRAPH 8 ( A ) AND ( B ) AND IN THE SECOND SENTENCE OF PARAGRAPH 9 .
12 ACCORDING TO THE SECOND SENTENCE OF PARAGRAPH 9 PERSONS IN THE SECOND CATEGORY , THAT IS TO SAY THOSE REFERRED TO IN PARAGRAPH 8 ( B ) AND ( C ), MAY ' ' PAY CONTRIBUTIONS ONLY IN RESPECT OF PERIODS FOR WHICH THEY HAVE NOT YET PAID CONTRIBUTIONS UNDER THE LEGISLATION OF ANOTHER MEMBER STATE ' ' . IN OTHER WORDS , THEY ARE BARRED FROM ' ' BUYING-IN ' ' PERIODS WHICH , FROM THE POINT OF VIEW OF THE GERMAN LEGISLATION , ARE ACTUALLY MISSING , WHILST THEY CORRESPOND TO CONTRIBUTION PERIODS IN ANOTHER MEMBER STATE , EVEN THOUGH IT MAY BE IN THEIR INTERESTS TO DO SO BECAUSE , FOR INSTANCE , THEY DO NOT HAVE ANY OTHER PERIODS TO BE BOUGHT IN . IT IS THEREFORE SELF-EVIDENT THAT THE COMPETENT GERMAN INSTITUTIONS CANNOT REQUIRE THEM TO ' ' BUY-IN ' ' THOSE PERIODS EVEN THOUGH THEY ARE MORE RECENT THAN THE PERIODS TO BE ' ' BOUGHT-IN ' ' .
13 ON THE OTHER HAND , IN THE CASE OF WORKERS IN THE FIRST CATEGORY WHO DERIVE THE RIGHT TO ' ' BUY-IN ' ' DIRECTLY FROM THE GERMAN LEGISLATION , THE SITUATION PRIOR TO THE AMENDMENT OF PART C OF ANNEX V MAINTAINED . THEY MAY BUY-IN EVEN