Marks: P
97 reporting marks.
- PACYPrairie Central RailwayOperating railroad
- PAEPeoria & Eastern Railway; ConrailOperating railroad
- PALPaducah & Louisville RailwayOperating railroad
- PAMPittsburgh, Allegheny & McKees Rocks RailroadOperating railroad
- PAPXPullmans IncPrivate owner
- PARXPan American Railway CompanyPrivate owner
- PARYPrairie Trunk RailwayOperating railroad
- PASPan Am SouthernOperating railroad
- PAUTPennsylvania & Atlantic Railroad; ConrailOperating railroad
- PAXXPassenger Railcar Services CorporationPrivate owner
- PBFXIBP, Inc.; Tyson FoodsPrivate owner
- PBLPhiladelphia Belt Line RailroadOperating railroad
- PBLXPillsburyPrivate owner
- PBNEPhiladelphia, Bethlehem & New England RailroadOperating railroad
- PBRPatapsco & Back Rivers RailroadOperating railroad
- PBRRPrairie Belt RailroadOperating railroad
- PBVRPort Bienville RailroadOperating railroad
- PCPenn Central; Norfolk SouthernOperating railroad
- PCAPenn Central; Norfolk SouthernOperating railroad
- PCBPenn Central; Norfolk SouthernOperating railroad
- PCCXPeabody Coal CompanyPrivate owner
- PCEXGE Capital Rail ServicesPrivate owner
- PCFXPacific Car & Foundry CompanyPrivate owner
- PCIXShippers Car Line; ACF IndustriesPrivate owner
- PCMXPetro-Chem Marketing CompanyPrivate owner
- PCNPoint Comfort & Northern RailwayOperating railroad
- PCRCPanama Canal Railway Company; Kansas City Southern RailwayOperating railroad
- PCSXGE Capital Rail ServicesPrivate owner
- PCTXPioneer Cement Company of TexasPrivate owner
- PCYPittsburgh, Chartiers & Youghiogheny RailwayOperating railroad
- PDQXCastle Capital CorporationPrivate owner
- PEPacific Electric Railway; ConrailOperating railroad
- PECXPekin Energy CompanyPrivate owner
- PENXPenford Products CompanyPrivate owner
- PEPXPotomac Electric Power CompanyPrivate owner
- PERPort Everglades RailwayOperating railroad
- PFPioneer & Fayette RailroadOperating railroad
- PFEPacific Fruit Express; Union PacificOperating railroad
- PFMPower, Fluid & MetalsOperating railroad
- PGDXProcter & GamblePrivate owner
- PGEPacific Great Eastern Railway; British Columbia Railway; Canadian NationalOperating railroad
- PGERPacific Great Eastern Railway; British Columbia Railway; Canadian NationalOperating railroad
- PGEXPortland General Electric CompanyPrivate owner
- PGHXTrinity Rail ManagementPrivate owner
- PGMXProcter & GamblePrivate owner
- PGRProgressive RailOperating railroad
- PHCRPort Colborne Harbour RailwayOperating railroad
- PHDPort Huron & Detroit Railroad; Chessie System; CSXOperating railroad
- PHLPacific Harbor LineOperating railroad
- PIPaducah & Illinois RailroadOperating railroad
- PICKPickens RailroadOperating railroad
- PINXPinnacle PolymersPrivate owner
- PJRPort Jersey RailroadOperating railroad
- PLCXPullman Leasing Company; GE Capital Rail ServicesPrivate owner
- PLEPittsburgh & Lake Erie Railroad; New York Central Railroad; Penn Central; Conrail; CSXOperating railroad
- PLEXPLMPrivate owner
- PLLUPolynesia LinePrivate owner
- PLLZPolynesia LinePrivate owner
- PLMXPLM InternationalPrivate owner
- PLWXGE Capital Rail ServicesPrivate owner
- PMPere Marquette Railway; Chesapeake & Ohio Railway; Chessie System; CSXOperating railroad
- PMLXPrairie MaltPrivate owner
- PMRXProgress Metal Reclamation CompanyPrivate owner
- PNPiedmont & Northern Railway; Seaboard Coast Line; CSX · Pennsylvania Northeastern RailroadOperating railroad
- PNRWPiedmont & Northern RailwayOperating railroad
- PNWRPortland & Western RailroadOperating railroad
- PNWXPNW RailcarsPrivate owner
- POHCPittsburgh & Ohio Central RailroadOperating railroad
- POTBPort of Tillamook Bay RailroadOperating railroad
- PPAXPCS Phosphate CompanyPrivate owner
- PPCXAmerican Association of Private Railroad Car OwnersPrivate owner
- PPGXPPG IndustriesPrivate owner
- PPHXPCS Phosphate CompanyPrivate owner
- PPLXPennsylvania Power & Light CompanyPrivate owner
- PPNXPCS Phosphate CompanyPrivate owner
- PPRXPhillips Petroleum CompanyPrivate owner
- PPUPeoria & Pekin Union RailwayOperating railroad
- PRCX20th Century FoxPrivate owner
- PRGXProGoldPrivate owner
- PRLPenn Eastern Rail Lines; East Penn RailwayOperating railroad
- PRLXProgress Rail Services CorporationPrivate owner
- PRMUPuerto Rican Maritime Shipping AuthorityPrivate owner
- PROXProcorPrivate owner
- PRRPennsylvania Railroad; Penn Central; Norfolk SouthernOperating railroad
- PRRXNorfolk SouthernPrivate owner
- PRSLPennsylvania-Reading Seashore Lines; Norfolk SouthernOperating railroad
- PRSXProgress Rail Services CorporationPrivate owner
- PSPittsburg & Shawmut RailroadOperating railroad
- PSCXPublic Service Company of ColoradoPrivate owner
- PSIXPacific SteelPrivate owner
- PSLPeabody Short Line; Illinois Central Railroad; Canadian NationalOperating railroad
- PSPXPhillips Petroleum CompanyPrivate owner
- PSRPittsburg & Shawmut RailroadOperating railroad
- PTEXCanpotexPrivate owner
- PTLXPullman Transport Leasing; GE Capital Rail ServicesPrivate owner
- PTMPortland Terminal Company; Maine Central Railroad; Pan Am RailwaysOperating railroad
- PWProvidence & Worcester RailroadOperating railroad