| 3801 | RGMS | R & G MANUFACTURAS DE MEXICO SA DE | | | SCAC4 |
| 3802 | RGMW | RIO GRANDE MOTOR WAY INC | | | PWRC |
| 3803 | RGMW | RIO GRANDE MOTOR WAY, INC | | | SCAC3 |
| 3804 | RGN | Berlin European U.K. Ltd. | IATA: WZ, Callsign: Regional, Formerly Berlin Regional (UK) Ltd. Sold / intergrated into Germania on 01 April 1991. | GB | AVCODES |
| 3805 | RGN | Cygnus Air, S.A. | IATA: Y2, Callsign: Cygnus Air, IATA Prefix: 571, Name changed from Regional Lineas Aereas. ICAO callsign changed from Regional Lineas. Designator XG* recalled by IATA | E | AVCODES |
| 3806 | RGN | Berlin European U.K. Ltd. | IATA: FB, Callsign: Regional, IATA Desigantor changed to WZ | GB | AVCODES |
| 3807 | RGN | Corporacion Ygnus Air, S.A. | Callsign: Cygnus Air, Designator Y2* recalled by IATA. Name changed from Regional Lineas Aereas. ICAO callsign changed from Regional Lineas. Designator XG* recalled by IATA | E | AVCODES |
| 3808 | RGN | Cygnus Air | | | ICAO1 |
| 3809 | RGNA | RAGONA, DON TRUCKING | | | SCAC3 |
| 3810 | RGNB | ROGERS & BROWN | | | SCAC4 |
| 3811 | RGNC | REGENCY MOVING & STORAGE CO INC | | | SCAC4 |
| 3812 | RGND | REGENCY TRANSPORTATION INC (DEDICAT | | | SCAC4 |
| 3813 | RGNE | REGAN, ED PRINTING MACHINERY MOVERS | | | SCAC3 |
| 3814 | RGNE | REGENCY EXPRESS CO LTD, THE | | | SCAC4 |
| 3815 | RGNH | RAGNHILD SHIPPING COMPANY LIMITED | | | SCAC3 |
| 3816 | RGNH | REGIONAL HAULAGE | | | SCAC4 |
| 3817 | RGNL | REGIONAL TRANSPORTATION INC | | | SCAC3 |
| 3818 | RGNL | RIGAR INTERNATIONAL | | | SCAC4 |
| 3819 | RGNM | REGENTIK TRUCKING | | | SCAC3 |
| 3820 | RGNO | RIGGINS INC | | | SCAC4 |
| 3821 | RGNQ | REGAN, DENNIS EQUIPMENT RENTAL | | | SCAC3 |
| 3822 | RGNQ | REGENCY MOVING & STORAGE CO INC | | | SCAC4 |
| 3823 | RGNS | RAMSAY, GEORGE & SONS INC | | | SCAC4 |
| 3824 | RGNT | REGENCY TRANSPORTATION INC | | | SCAC3 |
| 3825 | RGNT | REGENCY TRANSPORTATION INC | | | SCAC4 |
| 3826 | RGNX | RAILGON COMPANY | | | PWRC |
| 3827 | RGNX | TTX COMPANY | | | SCAC4 |
| 3828 | RGNY | REGENCY LIMITED | | | SCAC3 |
| 3829 | RGNY | ROOTED & GROUNDED NURSERY LLC | | | SCAC4 |
| 3830 | RGO | Argo, S.A. | Callsign: Argos, founded in 1971. Ceased operations during 1987. | DOM | AVCODES |
| 3831 | RGO | Regional Linhas Aeréas Ltda | Callsign: Passaro, | BR | AVCODES |
| 3832 | RGO | Argo | | | ICAO1 |
| 3833 | RGOC | REGAL OIL COMPANY INC | | | SCAC4 |
| 3834 | RGOL | REGIONAL ASSOCIATES INC | | | SCAC4 |
| 3835 | RGOM | ROGOVIN MOVING & STORAGE CO INC | | | SCAC3 |
| 3836 | RGOP | RIO GRANDE OIL COMPANY | | | SCAC4 |
| 3837 | RGOT | RESTIGOUCHE TRANSPORT LIMITED | | | SCAC4 |
| 3838 | RGOX | Richfield Oil Corp. | 7/1937-4/1938 | | NAKINA |
| 3839 | RGOX | Rio Grande Oil Co. | 8/1920-7/1935 | | NAKINA |
| 3840 | RGOX | Richfield Oil Co. of California (Richfield Oil Corp.) | Apr-38 | | NRHS |
| 3841 | RGOX | *RICHFIELD OIL CORP. [RIO GRANDE OIL CO.] | | | PWRC |
| 3842 | RGOX | *RAILGON COMPANY | | | PWRC |
| 3843 | RGOX | TTX COMPANY | | | SCAC4 |
| 3844 | RGP | River State Government of Nigeria | Callsign: Garden City, | WAN | AVCODES |
| 3845 | RGP | River State Government of Nigeria | | | ICAO1 |
| 3846 | RGPA | RODRIGUEZ GUTIERREZ, PATRICIA | | | SCAC4 |
| 3847 | RGPE | RGP ENTERPRISES INC | | | SCAC4 |
| 3848 | RGPI | RADIX GROUP INTERNATIONAL | | | SCAC3 |
| 3849 | RGPL | RANGER PETROLEUM LLC | | | SCAC4 |
| 3850 | RGPN | RE-GAL TRANSPORTATION INC | | | SCAC3 |
| 3851 | RGPO | R G TRANSPORT INC | | | SCAC3 |
| 3852 | RGPO | R G TRANSPORT LLC | | | SCAC4 |
| 3853 | RGPQ | R T I GROUP INC | | | SCAC4 |
| 3854 | RGPR | RED DOG CORPORATION | | | SCAC3 |
| 3855 | RGPS | RGP TRANSPORTES | | | SCAC4 |
| 3856 | RGPX | Royal Gas Products Corp. | added 4/1960; 4/1961; eliminated 10/1961 | | NAKINA |
| 3857 | RGPX | Royal Gas Products Corp. | Apr-61 | | NRHS |
| 3858 | RGPX | ROYAL GAS PRODUCTS CORP. | | | PWRC |
| 3859 | RGQS | REGENT QUINCE SHIPPING CO LTD | | | SCAC3 |
| 3860 | RGR | Region Air, Inc. | Callsign: Regionair, | CDN | AVCODES |
| 3861 | RGR | Avior Regional, C.A. | IATA: 3R, Callsign: Avior Regional, Designator 9V recalled by IATA | YV | AVCODES |
| 3862 | RGR | Avior Regional, C.A. | Callsign: Avior Regional, Designator 9V recalled by IATA | YV | AVCODES |
| 3863 | RGR | Region Air | | | ICAO1 |
| 3864 | RGRA | ROGERS, RALPH A | | | SCAC3 |
| 3865 | RGRA | RICO GUERRA, GABINO | | | SCAC4 |
| 3866 | RGRC | RODRIGUE, RICHARD | | | SCAC4 |
| 3867 | RGRD | ROGERS DEDICATED SERVICES, INC | | | SCAC3 |
| 3868 | RGRD | ROGERS DEDICATED SERVICES INC | | | SCAC4 |
| 3869 | RGRE | RIG RUNNER EXPRESS | | | SCAC3 |
| 3870 | RGRE | RODRIGUE, RHEAUME BERNARD | | | SCAC4 |
| 3871 | RGRF | ROGERS FARMS | | | SCAC3 |
| 3872 | RGRF | ROUGE RIVER FARMS INC | | | SCAC4 |
| 3873 | RGRG | RAAB, GEORGE | | | SCAC4 |
| 3874 | RGRI | RAGER, RONALD INC | | | SCAC3 |
| 3875 | RGRK | RODGERS TRUCKING | | | SCAC3 |
| 3876 | RGRL | REGOGO RACING LLC | | | SCAC4 |
| 3877 | RGRN | ROGERS TRUCKING INC | | | SCAC3 |
| 3878 | RGRN | RIG RUNNERS INC | | | SCAC4 |
| 3879 | RGRO | RAMBLING ROSE TRUCKING | | | SCAC4 |
| 3880 | RGRR | ROGERS TRANSPORT SYSTEMS LLC | | | SCAC4 |
| 3881 | RGRS | ROGERS, C J TRANS CO | | | SCAC3 |
| 3882 | RGRS | ROGERS FOODS LTD | | | SCAC4 |
| 3883 | RGRT | ROGERS TOWING SERVICE | | | SCAC4 |
| 3884 | RGRTA | Rochester-Genesee Regional Transportation Authority | | USA | TRAFFIC |
| 3885 | RGRU | COMBS INVESTMENT PROPERTY LP | | USA | BIC |
| 3886 | RGRW | REGIONAL RELOCATION & WAREHOUSING I | | | SCAC3 |
| 3887 | RGRW | REGIONAL RELOCATION & WAREHOUSING I | | | SCAC4 |
| 3888 | RGRX | Rio Grande Railcar Co., Inc. | 1/1994-7/2005 (not listed) | | NAKINA |
| 3889 | RGRX | Rio Grande Railcar Co., Inc. | 1/94-7/2000 | | NRHS |
| 3890 | RGRX | RIO GRANDE RAILCAR COMPANY, INC. | | | PWRC |
| 3891 | RGRX | Rio Grande Railcar | | | RSRV |
| 3892 | RGRX | RIO GRANDE RAILCAR COMPANY, INC. | | | SCAC4 |
| 3893 | RGRY | ROBLES GONZALEZ, REY DAVID | | | SCAC4 |
| 3894 | RGRZ | CSX TRANSPORTATION, INC. | | | PWRC |
| 3895 | RGS | Renown Aviation, Inc. | Callsign: Renown, | USA | AVCODES |
| 3896 | RGS | Renown Aviation | | | ICAO1 |
| 3897 | RGS | RIO GRANDE SOUTHERN RAILROAD | | | PWRC |
| 3898 | RGS | Rio Grande Southern Railroad | | | RSRV |
| 3899 | RGS | Rio Grande Southern | | USA | TRAFFIC |
| 3900 | RGSA | RIGEL SCHIFFAHRTS GMBH | | | SCAC3 |
