| 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 |