UNIX: Uniplex Information and Computing System
UNMEE: United Nations Mission in Ethiopia & Eritrea
UNMIBH: United Nations Mission in Bosnia & Herzegovina
UNMIH: United Nations Mission in Haiti
UNMIK: United Nations Mission in Kosovo
UNMIL: United Nations Mission in Liberia
UNMISET: United Nations Mission of Support in East Timor
UNMO: United Nations Military Observer
UNMO: United Nations Military Observers
UNMOGIP: United Nations Military Observer Group in India and Pakistan
UNMSC: United Nations Military Staff Committee
UNODIR: unless otherwise directed
UNOMIL: United Nations Observer Mission in Liberia
UNOSOM: United Nations Operations in Somalia
UNOSOM II: United Nations Operation in Somalia II
UNPOL: United Nations Police
UNPP: UN Peace Plan
UNPROFOR: United Nations Protection Force
UNREF: United Nations Refugee Fund
UNREP: Underway Replenishment
UNRWA: United Nations Relief & Works Agency
unsat: unsatisfactory

UNSC: United Nations Security Council
UNSC: United Nations Space Command
UNSCR: United Nations Security Council Resolution
UNTAET: United Nations Transitional Authority East Timor
UNTSO: United Nations Truce Supervision Organization
UNTSU: United Nations Terrorist Support Unit
UO: Urban Operations
UO: Using Organization

UOR: Urgent Operational Requirement
UPC: Usage Parameter Code
UPI: United Press International
UPOS: University Partnering for Operational Support
UPP: User Partnership Program
UPS: Uninterruptible Power Supply
UPS: Uninterruptible Power System
UPS: Universal Polar Stereographic
UPT: Universal Personal Telecommunications
UQL: Universal Query Language