1 . QUESTIONS SUBMITTED FOR A PRELIMINARY RULING - REFERENCE TO THE COURT - RIGHT OF EVERY NATIONAL COURT - STAGE OF THE PROCEEDINGS BEFORE THE NATIONAL COURT - NATURE OF THE DECISION TO BE GIVEN BY THE NATIONAL COURT - IRRELEVANT ( EEC TREATY , ART . 177 , SECOND PARA .) 2 . COMMUNITY LAW - DIRECT EFFECT - NATIONAL CHARGES INCOMPATIBLE WITH COMMUNITY LAW - REPAYMENT - PROCEDURES - APPLICATION OF NATIONAL LAW - LIMITS 3 . COMMUNITY LAW - DIRECT EFFECT - NATIONAL CHARGES INCOMPATIBLE WITH COMMUNITY LAW - REPAYMENT - PROCEDURES - APPLICATION OF NATIONAL LAW - CONDITIONS - CONSIDERATION OF POSSIBLE PASSING ON OF THE CHARGE - PERMISSIBILITY 4 . COMMUNITY LAW - DIRECT EFFECT - NATIONAL CHARGES INCOMPATIBLE WITH COMMUNITY LAW - REPAYMENT - PROCEDURES - APPLICATION OF NATIONAL LAW - CONDITIONS - REQUIREMENT OF PROOF THAT THE TAXPAYER HAS NOT PASSED THE CHARGES ON - UNACCEPTABILITY - CRITERIA