The Amalgamated Drawing Office was the design and engineering department of the British Motor Corporation. From the early 1950s, the resulting projects of the office were known by the initials ADO. The numbers were assigned to vehicle and engineering projects, some resulting in production models. The ADO numbering system continued well beyond BMC's absorption into British Leyland, who continued to use the convention (not, however on any former Leyland Motors marques such as Rover or Triumph) until the late 1970s.