From QRZ.Com, the Icom handout, and Part 97 Of The FCC Rules -
Ham Radio Glossary - An overview of amateur radio terms.

UHF
(ultra-high frequency). The frequency range 300-3000 MHz (3 Ghz) range.

ULS
(Universal Licensing System). The consolidated database, application
filing system and processing system for all Wireless Telecommunications Services.

Uplink
Frequency that transmits to the repeater or satellite. Also see Downlink.

USB
Upper Sideband

UTC
Coordinated Universal Time; a single time reference to be used worldwide (reduces the confusion that can occur when considering multiple time
zones). The time is based on the areas crossing the Greenwich Meridian,
and was also called GMT for Greenwich Mean Time. This is also known as
"Z Time".
--- SBBSecho 3.20-Win32
* Origin: The Thunderbolt BBS - Little Rock, Arkansas (1:2320/33)