| 1 | ROC | Rocky Mountain Airlines | | CDN | AVCODES |
| 2 | ROC | Rocky Mountain Airlines | | | ICAO1 |
| 3 | ROCA | R O C TRANSPORT INC | | | SCAC4 |
| 4 | ROCA | Republic of China Army | | RC | TRAFFIC |
| 5 | ROCB | ROSALES OIL COMPANY | | | SCAC4 |
| 6 | ROCD | ROCHESTER CITY DELIVERY INC | | | SCAC3 |
| 7 | ROCD | ROCHESTER CITY DELIVERY INC | | | SCAC4 |
| 8 | ROCF | ROBBINS FARMS | | | SCAC4 |
| 9 | ROCH | ROWAYTON FUEL & OIL CO INC | | | SCAC4 |
| 10 | ROCI | RANCHERS OIL CO | | | SCAC3 |
| 11 | ROCJ | ROCHE MOVING & STORAGE INC | | | SCAC3 |
| 12 | ROCK | Chicago, Rock Island and Pacific Ry. Co. | added 7/1975; 1/1980; eliminated 7/1980 | | NAKINA |
| 13 | ROCK | Chicago, Rock Island and Pacific Ry. Co. | added 7/75; 1/80; eliminated 7/80 | | NRHS |
| 14 | ROCK | CHICAGO, ROCK ISLAND & PACIFIC RAILROAD (ROCK ISLAND) | | | PWRC |
| 15 | ROCK | Chicago, Rock Island and Pacific Railroad | | | RSRV |
| 16 | ROCK | Chicago, Rock Island and Pacific Ry. Co | 1975 - 1980 | USA | TRAFFIC |
| 17 | ROCKLAND | Rockland Coaches | A Coach USA company | USA | TRAFFIC |
| 18 | ROCL | ROSS, C L INC | | | SCAC3 |
| 19 | ROCL | RAPID OCEAN CO LTD | | | SCAC4 |
| 20 | ROCM | RICH OIL COMPANY INC | | | SCAC4 |
| 21 | ROCM | Republic of China Marine Corps | | RC | TRAFFIC |
| 22 | ROCN | ROCOR TRANSPORTATION COMPANIES | | | SCAC3 |
| 23 | ROCN | RORO COMPANY LTD | | | SCAC4 |
| 24 | ROCO | ROC MOVING & STORAGE | | | SCAC3 |
| 25 | ROCO | ROC MOVING & STORAGE | | | SCAC4 |
| 26 | ROCO | | | X | TRAFFIC |
| 27 | ROCQ | ROCKFORD-AURORA MOTOR SERVICE INC | | | SCAC3 |
| 28 | ROCQ | ROAD KING & LOGISTIC INC | | | SCAC4 |
| 29 | ROCS | RIO GRANDE CARRIERS INC | | | SCAC4 |
| 30 | ROCU | ROLAND UMSCHLAGSGESELLSCHAFT | | D | BIC |
| 31 | ROCU | AMERICAN ORIENTAL ENTERPRISES CO LT | | | SCAC4 |
| 32 | ROCV | ROCCO VAN & STORAGE CO | | | SCAC3 |
| 33 | ROCW | ROSE CITY MOVING & STORAGE INC | | | SCAC3 |
| 34 | ROCW | ROADLINK EXPRESS INC | | | SCAC4 |
| 35 | ROCX | Rocky Mountain Transportation Services | added 7/1995; 7/2000-7/2005 | | NAKINA |
| 36 | ROCX | Rock Island Improvement Co. | added 1/1979; 1/1980; eliminated 7/1980 | | NAKINA |
| 37 | ROCX | Rock Island Improvement Co. | added 1/79; 1/80; eliminated 7/80 | | NRHS |
| 38 | ROCX | Rocky Mountain Transportation Services | added 7/95; 7/2000 | | NRHS |
| 39 | ROCX | *ROCK ISLAND IMPROVEMENT COMPANY (ROCK ISLAND) | | | PWRC |
| 40 | ROCX | +ROCKY MOUNTAIN TRANSPORTATION SERVICES | | | PWRC |
| 41 | ROCX | Rock Island Improvement (Rocky Mountain Transportation Services) | | | RSRV |
| 42 | ROCX | ROCKY MOUNTAIN TRANSPORTATIN SERVIC | | | SCAC4 |
| 43 | ROCY | ROBERTS CARRIER CORPORATION | | | SCAC3 |
