UA - User Agent

UAA - Universally Address

UAA - Universally Administered Address

UAC - User Assurance Coordination

UAE - Unrecoverable Applications Error

UAM - User Authentication Method

UAPI - Universal Asynchronous Protocol Interface

UART - Universal Asynchronous Receiver - Transmitter

UBNS - Upper Bound on Network Size

UBR - Unspecified Bit Rate

UCE - Unsolicited Commercial E-mail

UCL - Universal Communications Language

UCPC - Useful Character Part with Coordinates

UCPP - Useful Character Port with Projection

UCS - Unicode Conversion Support

UCS - Universal Character Set

UCS - User Coordinate System

UCT - Universal Coordinated Time

UDAO - Universal Data Access Object

UDC - User Defined Commands

UDC - Universal Decimal Classification

UDE - Universal Data Exchange

UDEC - Universal Digital Electronic Computer

UDF - User Defined Functions

UDF - Universal Disk Format