| 1 | PRR | Paramount Airlines Limited | Callsign: Paramount, | WAL | AVCODES |
| 2 | PRR | Paramount Airlines | | | ICAO1 |
| 3 | PRR | Norfolk Southern R.R. Co. (Norfolk Southern) | added 7/1999; 7/2000-7/2005 | | NAKINA |
| 4 | PRR | Consolidated Rail Corp. | added 4/1976; 1/1980-1/1994; eliminated 7/1999 | | NAKINA |
| 5 | PRR | Penn Central Transportation Co., Robert W. Blanchette, Richard C. Bond and John H. McArthur, Trustees | eliminated 4/1976 | | NAKINA |
| 6 | PRR | Penn Central Transportation Co. | 4/1970-1/1975 | | NAKINA |
| 7 | PRR | Pennsylvania R.R. | 4/1938-10/1966 | | NAKINA |
| 8 | PRR | Pennsylvania R.R. | 4/38-10/66 | | NRHS |
| 9 | PRR | Penn Central Transportation Co. | 4/70-1/75 | | NRHS |
| 10 | PRR | Penn Central Transportation Co., Robert W. Blanchette, Richard C. Bond and John H. McArthur, Trustees | eliminated 4/76 | | NRHS |
| 11 | PRR | Consolidated Rail Corp. | added 4/76; 1/80-1/94; eliminated 7/99 | | NRHS |
| 12 | PRR | Norfolk Southern R.R. Co. (Norfolk Southern) | added 7/99; 7/2000 | | NRHS |
| 13 | PRR | *P & R RAIL CAR SERVICE CORP. | | | PWRC |
| 14 | PRR | +NORFOLK SOUTHERN RWY. [CONRAIL; PENN CENTRAL; PENNSYLVANIA RR] | | | PWRC |
| 15 | PRR | Pennsylvania Railroad (Norfolk Southern) | | | RSRV |
| 16 | PRR | PRESCOTT TRANSIT AUTHORITY | | | SCAC4 |
| 17 | PRR | Pennsylvania Railroad | | USA | TRAFFIC |
| 18 | PRRA | PREMIER TRANSPORT LTD | | | SCAC3 |
| 19 | PRRC | PERROTT, SR CHARLES T | | | SCAC3 |
| 20 | PRRD | PROMPT REFRIGERATED TRANSPORT INC | | | SCAC3 |
| 21 | PRRE | PANKAR MARITIME S A | | | SCAC3 |
| 22 | PRRE | PANKAR MARITIME S A | | | SCAC4 |
| 23 | PRRF | PROMES, RAYNOLD F | | | SCAC3 |
| 24 | PRRG | PERRY RIGGING AND STORAGE | | | SCAC3 |
| 25 | PRRH | PARRISH TRUCKING CO INC | | | SCAC3 |
| 26 | PRRH | PARRISH TRUCKING CO INC | | | SCAC4 |
| 27 | PRRL | PARSONS, R L INC | | | SCAC3 |
| 28 | PRRM | PRIORITY MAIL (DIV OF USPS) | | | SCAC3 |
| 29 | PRRN | PRIOR TRUCKING CO | | | SCAC3 |
| 30 | PRRN | PIRRONE, MIKE PRODUCE INC | | | SCAC4 |
| 31 | PRRP | PARRCO ENTERPRISES | | | SCAC3 |
| 32 | PRRP | PERRAS LUMBER INC | | | SCAC4 |
| 33 | PRRQ | PARRY | | | SCAC3 |
| 34 | PRRR | POIRIER, RICHARD | | | SCAC4 |
| 35 | PRRS | PRIM RE-FER SERVICE INC | | | SCAC3 |
| 36 | PRRT | PARSONS, ROBERT TRUCKING | | | SCAC3 |
| 37 | PRRW | PREMIER TOURS | | | SCAC3 |
| 38 | PRRX | Pennsylvania Lines LLC | 7/2000-7/2005 (not listed) | | NAKINA |
| 39 | PRRX | Pennsylvania Lines LLC | Jul-00 | | NRHS |
| 40 | PRRX | *PENNSYLVANIA RAILROAD HISTORICAL EQUIPMENT CORPORATION | | | PWRC |
| 41 | PRRX | *POWELL RIVER RAILROAD COMPANY | | | PWRC |
| 42 | PRRX | +PENNSYLVANIA LINES LLC | | | PWRC |
| 43 | PRRX | Pennsylvania Railroad (Norfolk Southern) | | | RSRV |
| 44 | PRRX | PENNSYLVANIA LINES LLC | | | SCAC4 |
