Off-topic, but I think that traditionally, the longest official word in German was "Rindfleischetikettierungsüberwachungsaufgabenübertragungsgesetz", the name f

Off-topic, but I think that traditionally, the longest official word in German was "Rindfleischetikettierungsüberwachungsaufgabenübertragungsgesetz", the name for a law about testing and labeling of beef, now repealed. This word (63 letters) was of course not in everyday use by most people, but it was actually in the law.