| Category code | Explanation |
| J | Regular flight (Scheduled flight) |
| C | Non regular flight (Charter flight) |
| T1 | First visit (Type) |
| AT1 | First visit (Company type) |
| R1 | First visit (Registration) |
| L | Last flight / Departure |
| P | Delivery / Ferry flight |
| S | Sanitary / Ambulance flight |
| MP | Military (Fuel stop / Ferry flight) |
| M1 | Military (First visit) |
| V | VIP flights / Government types |
| EJ | Emergency / Diversion (Regular type) |
| E1 | Emergency / Diversion (First visit) |
| O | Other |