| Abbreviation | Definition |
|---|---|
| UOA | Underused Overrated Acronyms |
| UOB | U Owe Bob |
| UOCC | Ultima Online Celebrity Chat |
| UOK | Are You OK? |
| UOL | U Owe Larry |
| UOM | U Owe Me |
| UOMBT | You Owe Me Big Time |
| UOP | U Owe Paul |
| UOS | U Owe Sam |
| UPAT | Once Upon A Time |
| UPL | Usenet Posting License |
| UPR | Unconditional Positive Regard |
| UPS | Utter Parcel S*** |
| UPY | Up Yours! |
| UQ | Un-necessary Quotation |
| UQT | You Cutie |
| UR | Usage Rating |
| UR | You Are .... |
| URA* | yoU aRe A Star |
| URAL | You Are A Loser |