 Whilst the wooden variants were exclusively built as 4th class coaches, the iron ones were delivered as 2nd, 3rd, 4th, 2nd/3rd and even 2nd/4th class coaches.In a succession of procurement programmes, a further 517 4th class, all-steel coaches (440 in "Austauschbauart" form) were acquired in 1927/28, followed by a total of 5,009 coaches of 2nd, 3rd, 4th, 2nd/3rd and 3rd/4th classes (of which 3,377 were "Austauschbauart" versions) from 1928 to 1930, so that by 1930 more than 8,250 coaches had entered service.In 1928, when the Reichsbahn dropped the 4th class grade of accommodation, the 4th class coaches, which had initially been the largest group, were redesignated as 3rd class coaches at first and then, later, converted.