| 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 | 
| DR | Driving | 
| 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 |