In 1922 the Deutsche Reichsbahn began to develop a renumbering plan to standardize the numbering of steam locomotives that had been taken over from the state railways (Länderbahnen). Its basis was the corresponding DRG classification system.
1. In 2003, Cumpston wrote the original National DRG Implementation for Turkish hospitals, which was ratified and implemented by Turkish Premier Tayyip Erdogan in 2004.