| 1 | OPS | Jet Ops | IATA: J6, Callsign: Ops-Jet, Designator J6* recalled by IATA | UAE | AVCODES |
| 2 | OPS | Jet Ops | Callsign: Ops-Jet, Designator J6* recalled by IATA | UAE | AVCODES |
| 3 | OPS | Jet-Ops | | | ICAO1 |
| 4 | OPSA | OPERADORA DE TRANSPORTE INTERNACION | | | SCAC4 |
| 5 | OPSB | OCEAN PRIDE SEAFOODS LTD | | | SCAC4 |
| 6 | OPSC | OVERSEAS PUGET SOUND CHARTERER LLC | | | SCAC4 |
| 7 | OPSE | OCEAN PACIFIC SEAFOOD | | | SCAC4 |
| 8 | OPSI | OLYMPIC PAVING STONE INC | | | SCAC4 |
| 9 | OPSL | OFFICIAL LIST OF OPEN AND PREPAY ST | | | SCAC3 |
| 10 | OPSM | OPEN SEA MARITIME CORPORATION | | | SCAC3 |
| 11 | OPSP | OCEAN PORT SERVICES CORP | | | SCAC4 |
| 12 | OPSQ | OCEAN PRINCESS SHIPPING LIMITED | | | SCAC3 |
| 13 | OPSQ | OCEANPRINCE INVESTMENTS LTD | | | SCAC4 |
| 14 | OPSS | OCEAN PORT SERVICES LLC | | | SCAC4 |
| 15 | OPSU | EMP | | | PWRC |
| 16 | OPSX | Public Service Co. of Oklahoma | added 1/1979; 1/1980-7/2005 | | NAKINA |
| 17 | OPSX | Public Service Co. of Oklahoma | added 1/79; 1/80-7/2000 | | NRHS |
| 18 | OPSX | PUBLIC SERVICE COMPANY OF OKLAHOMA | | | PWRC |
| 19 | OPSX | Public Service of Oklahoma | | | RSRV |
| 20 | OPSX | PUBLIC SERVICE COMPANY OF OKLAHOMA | | | SCAC4 |