1 . ACTION FOR FAILURE OF A STATE TO FULFIL ITS OBLIGATIONS - COMPATIBILITY OF NATIONAL MEASURES WITH COMMUNITY LAW - CONSIDERATION BY THE COMMISSION - DUTY TO TAKE ACTION WITHIN A GIVEN PERIOD - NONE ( EEC TREATY , ART . 169 ) 2.TAXATION PROVISIONS - HARMONIZATION OF LEGISLATION - TURNOVER TAXES - COMMON SYSTEM OF VALUE ADDED TAX - BASIS OF ASSESSMENT - NATIONAL DEROGATIONS - LIMITS ( SIXTH COUNCIL DIRECTIVE ( 77/388/EEC ), ARTS 11 AND 27 ( 1 ) AND ( 5 ))