A1       Amateur
A2       Air Transport Rating (ATR)
A3       Airplane
A4       American Motorcyclist Association (AMA)
A5       American Powerboat Association (APBA)
B1       Boeing 747
D1       Deep Water Diver Club
D2       Diving Advanced Open Water Certification
D3       Diving Open Water Certification
D4       Diving Rescue Diver Certification
D5       Diving Underwater Hunter Certification
F1       Federal Aviation Administration Medical Class 1
F2       Federal Aviation Administration Medical Class 2
F3       Federal Aviation Administration Medical Class 3
G1       Glider
I1       Instructor
I2       International Motor Sports Association (IMSA)
I3       Instrument
I4       Instrument Flight Rating Airplane
I5       Instrument Flight Rating Helicopter
L1       Lighter Than Air
M1       Multiengine Land
M2       Multiengine Sea
N1       National Association Stock Car Auto Racing (NASCAR)
N2       National Hot Rod Association (NHRA)
P1       Professional
R1       Rotorcraft
S1       Student
S2       Sports Car Club of America (SCCA)
S3       Single Engine Land
S4       Single Engine Sea
U1       United States Auto Club (USAC)
V1       Visual