I noticed this stenciled on the trucks of a MARC coach sitting in the station. These inscriptions are also found on other stuff on car and locomotive undercarriages. Around here the inscription reads "Washington, D.C. COT&S." What do these inscriptions mean? I can imagine an archeologist digging up one of these 2,000 years from now and trying to decipher it. O course, given the wet climate of this region of the country, most of it will probably be rusted away by then.