| Abbreviation | Definition |
|---|---|
| TYC | Tylerdale Connecting |
| TYPX | Tyco Plastics |
| TYRR | Toronto & York Radial Railway |
| TYSSE | Toronto-York Spadina Subway Extension |
| TZPR | Tazewell and Peoria Railroad |
| TZR | Tanzania-Zambia Railway |
| UACU | United Arab Shippers |
| UACU | United Arab Shipping |
| UAEU | United Arab Shipping |
| UAEU | United Arab Shipping Company |
| UAIX | United Asphalts |
| UAIX | United Asphalts Incorporated |
| UASU | United Arab Shipping |
| UASU | United Arab Shipping Company |
| UASZ | United Arab Shipping |
| UASZ | United Arab Shipping Company |
| UBCU | United Fruit |
| UBCU | United Fruit Company |
| UBD | Union Belt of Detroit |
| UBMU | United Baltic Corporation Limited |