| Abbreviation | Definition |
|---|---|
| KTX | Keith Tank Line (ACF Industries Shippers Car Line) |
| KUCX | Kentucky Utilities |
| KUCX | Kentucky Utilities Company |
| KUR | Kenya Uganda Railway |
| KVR | Kern Valley Railroad |
| KWCU | World Container Leasing (Textainer) |
| KWCU | World Container Leasing Incorporated |
| KWT | K. W. T. Railway Incorporated |
| KWT | K.W.T. Railway |
| KWTR | Keota Washington Transportation |
| KWUX | Siemens Power Corporation |
| KWUX | Utility Power Corporation (Siemens Westinghouse Power Corporation) |
| KXHR | Knoxville and Holston River Railroad |
| KXHR | Knoxville and Holston River Railroad Company Incorporated |
| KYLE | Kyle Railroad |
| KYLE | Kyle Railroad Company |
| KYLU | N. Y. K. Line |
| KYLU | NYK Line |
| KYRX | David L. Joseph Co. (Progress Rail Services Corporation) |
| KYRX | Louisville Scrap Material Company |