| 24 | 24-hour Endurance Snowmobile |
| A1 | Aviation Advertising |
| A2 | Aerial Application |
| A3 | Aviation Aerobatics |
| A4 | Air Ambulance |
| A5 | Air Taxi |
| A7 | Auto Stunt Driving |
| A8 | Abalone Diving |
| A9 | Aerobatic Skydiving |
| AA | Auto Drag Racing |
| AB | Aviation Ferrying |
| AC | Aviation Firefighting |
| AD | Auto Hill Climbing |
| AE | Aviation Inspection |
| AF | Aviation Instructional |
| AH | Aviation Prospecting |
| AI | Auto Road Rally |
| B1 | Business Aviation |
| B2 | Base Jumping |
| B3 | Boxing |
| B4 | Bungee Jumping |
| B5 | Banner Towing |
| B6 | Bush Flying |
| C1 | Championship Auto Racing |
| C2 | Certificated Route Air Carrier |
| C3 | Chartered Air Carrier |
| C4 | Commercial Aviation |
| C5 | Construction Helicopter |
| C6 | Corporate Aviation |
| C7 | Crew Member Aviation |
| C8 | Cross-country Aviation |
| C9 | Cross-country Motorcycle Racing |
| CA | Cave Diving |
| CB | Cross-country Snowmobile Racing |
| CC | Cartography |
| CD | Cliff Soaring |
| D1 | Demolition Derby |
| D2 | Demonstration Aviation |
| E1 | Endurance Racing Inboard |
| E2 | Experimental Skydiving |
| F1 | Flying Used to send total hours flown in lifetime |
| F2 | Figure 8 Demolition |
| F3 | Formula or Grand Prix Auto Racing |
| F4 | Forestry Aviation |
| F5 | Fire Fighting |
| G1 | Glider or Sailplane |
| G2 | Grand Prix Motorcycle Racing |
| G3 | Ground Skimming |
| H1 | Hot-air Ballooning |
| H2 | Hang Gliding |
| H3 | Hydroplane Racing Unlimited |
| H4 | Hydroplane Racing Inboard |
| I1 | International Racing (Auto) |
| I2 | Intermediate Junior Snowmobile Racing |
| I3 | Ice Diving |
| I4 | Iceboat Racing |
| I5 | Inboard Racing |
| I6 | Ice Climbing |
| J1 | Jet Car Racing |
| J2 | Judo |
| K1 | Kart Racing |
| K2 | Karate |
| M1 | Midget Racing |
| M2 | Military Flying |
| M3 | Modified Outboard Racing |
| M4 | Motorboat Racing |
| M5 | Modified Stock Motorcycle Racing |
| M6 | Motocross Racing |
| M7 | Mountain Climbing |
| M8 | Military Skydiving |
| M9 | Modified Stock Snowmobile Racing |
| MA | Modified Snowmobile Racing |
| MB | Motorcycle Acrobatics |
| MC | Motorcycle Dirt Track Racing |
| MD | Motorcycle Drag Racing |
| ME | Motorcycle Enduro Racing |
| MF | Motorcycle Hill Climbing |
| MG | Motorcycle Ice Racing |
| MH | Motorcycle Observed Trials |
| MI | Motorcycle Road Racing |
| MJ | Motorcycle Road Riding |
| MK | Motorcycle Speed Record Trials |
| ML | Motorcycle Speedway |
| N1 | Non-scheduled Flying |
| O1 | Off Road Auto Racing |
| O2 | Offshore Racing |
| O3 | Outboard Performance Craft Racing |
| O4 | Oval Sprint Snowmobile Racing |
| O5 | Other |
| O6 | Open Modified Snowmobile Racing |
| P1 | Passenger Aviation |
| P2 | Personal Aviation |
| P3 | Photographic Aviation |
| P4 | Pilot Aviation |
| P5 | Pleasure Aviation |
| P6 | Precision Flying |
| P7 | Private Flying |
| P8 | Parachuting |
| P9 | Professional Outboard Racing |
| PA | Parakiting |
| PB | Parasailing |
| PC | Paraskiing |
| R1 | Rock Climbing |
| R2 | Rodeo |
| R3 | Ridge Soaring |
| S1 | Sports Car Racing |
| S2 | Sprint Car Racing |
| S3 | Stock Car Racing |
| S4 | Snowmobile Enduro Racing |
| S5 | Scheduled Flying |
| S6 | Sight Seeing Aviation |
| S7 | Student Flying |
| S8 | Stock Outboard Racing |
| S9 | Snowmobile Drag Racing |
| SA | Stock Snowmobile Racing |
| SB | Spear Fishing |
| SC | Scuba Diving |
| SD | Skydiving |
| SE | Skydiving Accuracy |
| SF | Skydiving Free-fall |
| SG | Stunt Flying |
| T1 | Testing Aviation |
| T2 | Traffic Watch Aviation |
| U1 | Underwater Diving |
| U2 | Underwater Hard-hat Diving |
| U3 | Underwater Scuba Diving |
| U4 | Underwater Skin Diving |
| W1 | Water Skiing |
| W2 | Wrestling |
| W3 | Wreck or Salvage Diving |
| W4 | World Snowmobile Speed Record |