Configuration Deviation List

A configuration deviation list (CDL) is a list established by the organization responsible for the type design with the approval of the State of Design which identifies any external parts of an aircraft type which may be missing at the commencement of a flight, and which contains, where necessary, any information on associated operating limitations and performance correction.(ICAO Annex 6: Operation of Aircraft)
The CDL is usually prepared by the aircraft manufacturer and is part of the AFM (Aircraft Flight Manual). The CDL should not be confused with the Minimum Equipment List (MEL).
The airlines MEL provides definitive guidance to flight crew, maintenance and operations personnel as to which items may be missing or damaged for particular operation. The Configuration Deviation List (CDL) may contain certificate limitations for operation of an aircraft with certain parts missing.