Source: KrasnayaZvezda, US forums

A note on nomenclature: Most people, who don't read the historical literature were used to the different nomenclature system: VK3002DB, which means "fully tracked vehicle, 30 tons, 2nd prototype, Daimler Benz". The D instead of DB means the same thing: Daimler Benz - just that one system is used by H. Doyle and the other by W. Spielberger. They both work the same.