| Abbreviation | Definition |
|---|---|
| UMS | Universal Mass Storage |
| UNH | University of No Hardware |
| UNIVAC | UNIVersal Automatic Computer |
| UNW | UNiqueWare devices |
| UOK | USB (Universal Serial Bus) power OK |
| uP | MicroProcessor |
| UPB | Universal Powerline Bus |
| UPIC | Unité Polyagogique Informatique de la CeMaMu. |
| UPL | Universal Price Label |
| UPS | Universal Port Serial |
| URA | Upper Removable Appliance |
| URD | Universal RAID (Redundant Array of Inexpensive Disks) Device |
| URE | Undetected Read Error |
| URE | Unrecoverable Read Error |
| URM | Universal Router Module |
| URP | Universal ROM (Read-Only Memory) Programmer |
| URP | Upper Receiver Parts |
| URPK | Upper Receiver Parts Kit |
| URPL | Upper Receiver Parts List |
| USART | Universal Synchronous/Asynchronous Receiver/Transmitter |