| 1 | MLD | Air Moldova | IATA: 9U, Callsign: Air Moldova, IATA Prefix: 572, Designator 9U reinstated by IATA | MD | AVCODES |
| 2 | MLD | Air Moldova | IATA: 9U | | ICAO1 |
| 3 | MLD | Midland | 1/1975-1/1980 | | NAKINA |
| 4 | MLD | Midland Ry. Co. of Manitoba | 4/1938-10/1966 | | NAKINA |
| 5 | MLD | Midland Ry. Co. of Manitoba | 4/38-10/66 | | NRHS |
| 6 | MLD | Midland | 1/75-1/80 | | NRHS |
| 7 | MLD | MIDLAND RY. CO. OF MANITOBA | | | PWRC |
| 8 | MLD | Midland Railway Co. of Manitoba | | | RSRV |
| 9 | MLD | Marineluchtvaartdienst | The Netherlands Naval Aviation Service (Dutch: Marineluchtvaartdienst) is the naval aviation branch of the Royal Netherlands Navy. | NL | TRAFFIC |
| 10 | MLDA | MATILDA SHIPPING LTD | | | SCAC4 |
| 11 | MLDE | MONARCH LITHO DE MEXICO S A DE C V | | | SCAC4 |
| 12 | MLDH | MANI | | | SCAC4 |
| 13 | MLDJ | MLD & SONS INDUSTRIES LLC | | | SCAC4 |
| 14 | MLDK | MACLEOD TRUCKING | | | SCAC4 |
| 15 | MLDM | MONROE, L D TRUCKING | | | SCAC4 |
| 16 | MLDO | MORENO, ALBERTO/LAREDO TRUCKING LLC | | | SCAC4 |
| 17 | MLDV | MAUL, DAVID | | | SCAC4 |
| 18 | MLDW | MANCHES | | | SCAC4 |