TAX PROVISIONS - HARMONIZATION OF LAWS - TURNOVER TAX - COMMON SYSTEM OF VALUE-ADDED TAX - TAX ON IMPORTATION - APPLICATION TO THE UNLAWFUL TRAFFIC IN DRUGS - NOT PERMISSIBLE - CRIMINAL SANCTIONS FOR OFFENCES - POWER OF THE MEMBER STATES ( COUNCIL DIRECTIVES 67/228 , ART . 2 AND 77/388 , ART . 2 )