| 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 |