U's

UAE - Unrecoverable Application Error
UART- Universal Asynchronous Receiver-Transmitter
UBR - Unspecified Bit Rate
UCM - Universal Cable Module
UDF - Universal Disk Format
UDP - User Datagram Protocol
UIC - User Identification Code
UL- Underwriters Laboratories
UL- Unordered List
UMA - Upper Memory Area
UMB - Upper Memory Block
UNC - Universal Naming Convention
UNI - User-To-Network Interface
UNIVAC- Universal Automatic Computer
UNMA- Unified Network Management Architecture
UPC - Universal Product Code
UPC - Usage Parameter Control
UPS - Uninterruptable Power Supply
URL - Uniform Resource Locator
USB - Universal Serial Bus
USENET- User Network
USL - Unix System Laboratory
USR - U.S. Robotics
UTP - Unshielded Twisted Pair
UUCP- Unix-to-Unix Copy Program