| Abbreviation | Definition |
|---|---|
| TXC | Transmission Complete flag |
| TXH | Transfer on High |
| TXH | Transmit High |
| U | Unconditional |
| U | Up |
| UA | Update Attribute |
| UAMA | Urban Assembly for Music and Art |
| UAU | Universal Assembly Unit |
| UB | Unsigned Byte |
| UC | Unreal Compile |
| UCE | Use Case Ends |
| UD | Update Data |
| UDA | User Defined Attribute |
| UDC | User Defined Codes |
| UDC | User Defined Command |
| UDF | User Defined Format |
| UDF | User Defined Function |
| UDL | User Defined Language |
| UDP | User Defined Procedure |
| UDR | Universal Data Representation |