| 1 | RSP | Raspet Flight Research Laboratory | Callsign: Raspet, | USA | AVCODES |
| 2 | RSP | Superior Air Charter, LLC d/b/a Jetsuite Air | Callsign: Red Stripe, | USA | AVCODES |
| 3 | RSP | Roscoe, Snyder & Pacific Ry. | 7/1965-10/1966 | | NAKINA |
| 4 | RSP | Roscoe, Snyder and Pacific Ry. Co. | 1/1994-7/2005 | | NAKINA |
| 5 | RSP | Roscoe, Snyder & Pacific Ry. | 4/1961 & 4/1970-1/1980; eliminated 1/1989; eliminated 4/1989 | | NAKINA |
| 6 | RSP | Roscoe, Snyder & Pacific Ry. | 4/61 & 4/70-1/80; eliminated 1/89; eliminated 4/89 | | NRHS |
| 7 | RSP | Roscoe, Snyder and Pacific Ry. Co. | 1/94-7/2000 | | NRHS |
| 8 | RSP | Roscoe, Snyder & Pacific Ry. | 7/65-10/66 | | NRHS |
| 9 | RSP | ROSCOE, SNYDER & PACIFIC RAILWAY CO. | | | PWRC |
| 10 | RSP | Roscoe, Snyder and Pacific Railway | | | RSRV |
| 11 | RSPA | RAVENNAVI SPA | | | SCAC3 |
| 12 | RSPA | RAILSIDE SPORTS & MARINE | | | SCAC4 |
| 13 | RSPB | REDEARTH SPIRIT | | | SCAC4 |
| 14 | RSPC | RISINGER BROS TRANSFER INC | | | SCAC4 |
| 15 | RSPE | ROSSINI SPECIALTIES LTD | | | SCAC3 |
| 16 | RSPG | RICHOCEAN SHIPPING AGENCY SA HONG K | | | SCAC3 |
| 17 | RSPI | R/S TRANSPORT INC | | | SCAC3 |
| 18 | RSPL | RONDEL SHIPPING LTD | | | SCAC3 |
| 19 | RSPL | RED STAR PETROLEUM LLC | | | SCAC4 |
| 20 | RSPM | ROSS PETROLEUM INC | | | SCAC4 |
| 21 | RSPN | R & S TRANSPORTATON | | | SCAC3 |
| 22 | RSPO | R & S TRANSPORTATION | | | SCAC3 |
| 23 | RSPO | R & S TRANSPORTATION INC | | | SCAC4 |
| 24 | RSPR | R & S TRANSPORT | | | SCAC3 |
| 25 | RSPR | ROLLE, S P TRUCKING | | | SCAC4 |
| 26 | RSPS | R S P EXPRESS INC | | | SCAC4 |
| 27 | RSPT | R S TRANSPORTATION | | | SCAC3 |
| 28 | RSPX | General Electric Railcar Services Corp. | added 10/1992; 1/1994; eliminated 10/1994 | | NAKINA |
| 29 | RSPX | Itel Rail Corp. | added 4/1988; eliminated 10/1992 | | NAKINA |
| 30 | RSPX | Evans Railcar Leasing Co. | added 10/1980; eliminated 4/1988 | | NAKINA |
| 31 | RSPX | United States Railway Leasing Co. | 1/1980; eliminated 10/1980 | | NAKINA |
| 32 | RSPX | United States Leasing Co. | added 7/1979 | | NAKINA |
| 33 | RSPX | United States Railway Equipment Co. | added 7/1970; 1/1975; eliminated 7/1979 | | NAKINA |
| 34 | RSPX | United States Railway Leasing Co. | added 4/1970; 4/1970; eliminated 7/1970 | | NAKINA |
| 35 | RSPX | RSP Car Co. | added 7/1960; 4/1961-10/1966; eliminated 4/1970 | | NAKINA |
| 36 | RSPX | RSP Car Co. | added 7/60; 4/61-10/66; eliminated 4/70 | | NRHS |
| 37 | RSPX | United States Railway Leasing Co. | added 4/70; 4/70; eliminated 7/70 | | NRHS |
| 38 | RSPX | United States Railway Equipment Co. | added 7/70; 1/75; eliminated 7/79 | | NRHS |
| 39 | RSPX | United States Leasing Co. | added 7/79 | | NRHS |
| 40 | RSPX | United States Railway Leasing Co. | 1/80; eliminated 10/80 | | NRHS |
| 41 | RSPX | Evans Railcar Leasing Co. | added 10/80; eliminated 4/88 | | NRHS |
| 42 | RSPX | Itel Rail Corp. | added 4/88; eliminated 10/92 | | NRHS |
| 43 | RSPX | General Electric Railcar Services Corp. | added 10/92; 1/94; eliminated 10/94 | | NRHS |
| 44 | RSPX | (NATX) GEN. ELECTRIC RAILCAR SERVICES CORP. [ITEL RAIL CORP.; EVANS RAILCAR LEASING CO.; U.S. RAILWAY LEASING CO.; RSP CAR CO.] | | | PWRC |
| 45 | RSPX | Evans Railcar Leasing (GE Railcar Services) | | | RSRV |
| 46 | RSPX | RSP CAR CO | | | SCAC3 |
| 47 | RSPZ | TRANSAMERICA LEASING INC [(REAZ) SOUTHERN PACIFIC TRANSP CO] | | | PWRC |
| 48 | RSPZ | TAL International (Union Pacific) | | | RSRV |
| 49 | RSPZ | TRANSAMERICA LEASING INC | | | SCAC4 |
