Opinion of Mr Advocate General Tesauro delivered on 7 March 1991. # Ludwig Post GmbH v Oberfinanzdirektion München. # Reference for a preliminary ruling: Bundesfinanzhof - Germany. # Common Customs Tariff - Tariff headings 0404 10 11 and 0404 90 33 - 75% whey protein concentrate. # Case C-120/90. Post TITJUR