| 1 | NOK | Sky Asia Co. Ltd. d/b/a Nok Air | IATA: DD, Name changed to Nok Airlines Co., Ltd. w.e.f. 18 January 2013 | T | AVCODES |
| 2 | NOK | Nok Airlines Company Limited | IATA: DD, Callsign: Nok Air, Sky Asia Co. Ltd. d/b/a Nok Air w.e.f. 16 Janaury 2006. Name changed to Nok Airlines Public Co., Ltd. d/b/a Nok Air w.e.f. 18 January 2013. | T | AVCODES |
| 3 | NOK | Nok Airlines Public Co., Ltd. d/b/a Nok Air | IATA: DD, Callsign: Nok Air, Filed for bankruptcy on 30 July 2020. Name changed from Nok Airlines Company Limited w.e.f. 18 January 2013 | T | AVCODES |
| 4 | NOK | Nok Air | IATA: DD | | ICAO1 |
| 5 | NOK | Nok Air | | T | TRAFFIC |
| 6 | NOKC | NORTH OAK CHRYSLER-PLYMOUTH INC | | | SCAC3 |
| 7 | NOKE | NEW ORLEANS TANKER CORPORATION | | | SCAC3 |
| 8 | NOKI | NAPCO TRUCKING INC | | | SCAC4 |
| 9 | NOKL | Northwestern Oklahoma R.R. Co. | 1/1975; added 1/1980; 1/1980-7/2005 | | NAKINA |
| 10 | NOKL | Northwestern Oklahoma R.R. Co. | 1/75; added 1/80; 1/80-7/2000 | | NRHS |
| 11 | NOKL | NORTHWESTERN OKLAHOMA RAILROAD CO. | | | PWRC |
| 12 | NOKL | Northwestern Oklahoma Railroad | | | RSRV |
| 13 | NOKL | NORTHWESTERN OKLAHOMA RAILROAD COMP | | | SCAC3 |
| 14 | NOKL | NORTHWESTERN OKLAHOMA RAILROAD COMP | | | SCAC4 |
| 15 | NOKL | Northwestern Oklahoma | | USA | TRAFFIC |
| 16 | NOKR | NORTHWESTERN OKLAHOMA RAILROAD CO. | | | PWRC |
| 17 | NOKR | Northwestern Oklahoma Railroad | | | RSRV |
| 18 | NOKR | NORTHERN TRUCKING SERVICE | | | SCAC3 |
| 19 | NOKS | NOAKES TRUCKING | | | SCAC3 |
| 20 | NOKU | NAUKA LINES PTE LTD | | IND | BIC |
| 21 | NOKZ | FIRST UNION RAIL | | | PWRC |
| 22 | NOKZ | First Union Rail | | | RSRV |
| 23 | NOKZ | FIRST UNION RAIL | | | SCAC4 |
