1. the far-reaching consequences of the EC Treaty provisions and principles for national tax law, as shown by the case law of the Court of Justice of the EC;
2. Community harmonization policy and coordination policy as regards indirect taxes and direct taxes;
3. Community law in force on indirect taxes (Value Added Tax, Community Customs Code, Excises and Energy Taxation);
4. Community law in force on direct taxes (Parent-Subsidiary Directive, Merger Directive, Interest and Royalties Directive, Transfer Pricing Arbitration Convention, Savings Interest Directive);
5. Administrative Assistance between the Member States in the assessment and the recovery of tax claims.