| Abbreviation | Definition |
|---|---|
| UCSB | Universal Character Set Buffer |
| UCW | Unit Control Word |
| UD | User Data |
| UD | User Defined |
| UDA | Universal Data Access |
| UDA | User Defined Assessments |
| UDC | Universal Disk Controller |
| UDD | Unified Data Descriptor |
| UDE | Unreal Development Environment |
| UDF | Universal Disk Format |
| UDF | User Defined Field |
| UDG | User Defined Graphic |
| UDK | User Defined Key |
| UDMA | Ultra Direct Memory Access |
| UDO | Universal Document Object |
| UDQ | UbiquinoX Device Query |
| UDT | Unreliable Data Transfer |
| UDX | Universal Data Xchange |
| UE | Unit of Execution |
| UE | User Event |