| 1 | CYX | American Cyanamid Co. | 8/1920-1/1980; eliminated 5/1983 | | NAKINA |
| 2 | CYX | American Cyanamid Co. | 4/38-1/80; eliminated 5/83 | | NRHS |
| 3 | CYX | RETIRED 04-03-92 (1081) ATP [AMERICAN CYANAMID CO.] | | | PWRC |
| 4 | CYX | American Cyanamid (Infinity Rail) | | | RSRV |
| 5 | CYXA | CURRY TRANSPORTATION INC | | | SCAC4 |
| 6 | CYXB | COYOTE TRANSPORTATION INC | | | SCAC4 |
| 7 | CYXC | COUNTY X PRESS INC | | | SCAC4 |
| 8 | CYXE | COUNTY LINE EXPRESS INC | | | SCAC4 |
| 9 | CYXI | CITY EXPRESS INC | | | SCAC3 |
| 10 | CYXO | CLUTCH CITY EXPRESS | | | SCAC4 |
| 11 | CYXP | CROWLEY EXPRESS SERVICE INC | | | SCAC3 |
| 12 | CYXP | CONROY EXPRESS | | | SCAC4 |
| 13 | CYXQ | CYTRA TRANSPORT INC | | | SCAC4 |
| 14 | CYXR | CITY XPRESS INC | | | SCAC3 |
| 15 | CYXV | CORNEY TRANSPORTATION SERVICES INC | | | SCAC4 |
| 16 | CYXX | Conrad Yelvington Distributors, Inc. | 7/2005 (not listed) | | NAKINA |
| 17 | CYXX | CONRAD YELVINGTON DISTRIBUTORS, INC | | | PWRC |
| 18 | CYXX | CONRAD YELVINGTON DISTRIBUTORS INC | | | SCAC4 |
| 19 | CYXX | Conrad Yelvington Distributors, Inc. | | USA | TRAFFIC |
