| 1 | YST | YOUNGSTOWN SHEET & TUBE CO. | | | PWRC |
| 2 | YST | YOUNGS TRANSPORTATION | | | SCAC4 |
| 3 | YSTC | Yverdon-Sainte Croix | | CH | TRAFFIC |
| 4 | YSTD | YAMASHITA-SHINNIHON LINE | | | PWRC |
| 5 | YSTK | YORK STATION TRUCKING | | | SCAC4 |
| 6 | YSTM | YAMASHITA-SHINNIHON LINE | | | PWRC |
| 7 | YSTN | YELLE, SYLVAIN TRANSPORT | | | SCAC4 |
| 8 | YSTP | YOSEMITY SAM TRANSPORT | | | SCAC4 |
| 9 | YSTR | YES TRANSPORT | | | SCAC4 |
| 10 | YSTS | YAMASHITA-SHINNIHON LINE | | | PWRC |
| 11 | YSTT | YAMASHITA-SHINNIHON LINE | | | PWRC |
| 12 | YSTU | YAMASHITA-SHINNIHON LINE | | | PWRC |
| 13 | YSTU | Yamashita-Shinnihon Line | | | RSRV |
| 14 | YSTX | The Youngstown Sheet & Tube Co. | 8/1920-4/1970; eliminated 7/1972; 1/1975-1/1980 | | NAKINA |
| 15 | YSTX | The Youngstown Sheet & Tube Co. | 4/38-1/80 | | NRHS |
| 16 | YSTX | RETIRED 02-19-91 FET (ACI 1677) [YOUNGSTOWN SHEET & TUBE CO.] | | | PWRC |
| 17 | YSTX | Youngstown Sheet and Tube | | | RSRV |
