The Bundeswehr’s salute regulation of 23 December 1955 set out how soldiers were to address each other. All superiors and all soldiers of higher rank groups were to be addressed with Herr and their rank, as in Herr Hauptmann. For subordinates, rank and surname were enough. Du was appropriate only where regional or comradely familiarity justified it, for example among enlisted men. A Luftwaffe officer cadet complained. On 25 March 1970 the Federal Administrative Court ruled that the one-sided rule violated the principle of equality in Article 3 of the Basic Law. The court did not object to the use of rank in address as such.