The statistical classifications are designed to reflect the operating elements attributable to each distinctive class of service offered. The operating elements shall be grouped in accordance with their inherent characteristics as follows:
U.S. Air Carriers:
K-Scheduled Services (F + G)
F-Scheduled Passenger/Cargo
G-Scheduled All-Cargo
Foreign Air Carriers:
F-Scheduled Passenger/Cargo
G-Scheduled All-Cargo
U.S. Air Carriers:
V-Nonscheduled Services (L + N + P + R)
L-Nonscheduled Civilian Passenger/Cargo
P-Nonscheduled Civilian Cargo
N-Nonscheduled Military Passenger/Cargo
R-Nonscheduled Military Cargo
Foreign Air Carriers:
L-Nonscheduled Civilian Passenger Cargo
P-Nonscheduled Civilian All-Cargo Charters
Q-Nonscheduled Services (Other than Charter)
U.S. Air Carriers:
Z-All Services (V + K)
14 C.F.R. §19-4