1 . TAX PROVISIONS - INTERNAL TAXES - DIFFERENTIATED TAX SYSTEM - PERMISSIBILITY - CONDITIONS ( EEC TREATY , ART . 95 ) 2 . TAX PROVISIONS - INTERNAL TAXES - TAXES INCOMPATIBLE WITH COMMUNITY LAW - OBLIGATIONS OF MEMBER STATES ( EEC TREATY , ART . 95 ) 3 . COMMUNITY LAW - DIRECT EFFECT - INDIVIDUAL RIGHTS - PROTECTION BY NATIONAL COURTS - PRINCIPLE OF CO-OPERATION ( EEC TREATY , ART . 5 ) 4 . TAX PROVISIONS - INTERNAL TAXES - TAXES INCOMPATIBLE WITH COMMUNITY LAW - REIMBURSEMENT BY MEMBER STATES - PROCEDURAL CONDITIONS - APPLICATION OF NATIONAL LAW - CONDITIONS - TAKING ACCOUNT OF ANY PASSING ON OF TAX OR OF DAMAGE SUFFERED BY THE IMPORTER - PERMISSIBILITY ( EEC TREATY , ART . 95 )