| U | You | - | ISO Country Codes |
| U UP | Are You Up? | - | ISO Country Codes |
| U-L | You Will | - | ISO Country Codes |
| U2 | You Too | - | ISO Country Codes |
| U8 | You Ate? | - | ISO Country Codes |
| UBS | Unique Buying State | - | ISO Country Codes |
| UCWAP | Up A Creek Without A Paddle | - | ISO Country Codes |
| UDH82BME | You'd Hate To Be Me | - | ISO Country Codes |
| UG2BK | You've Got To Be Kidding | - | ISO Country Codes |
| UGC | User-Generated Content | - | ISO Country Codes |
| UL | You Will | - | ISO Country Codes |
| UNPC | UnPolitically Correct | - | ISO Country Codes |
| UNTCO | You Need To Chill Out | - | ISO Country Codes |
| UOK | Are You OK? | - | ISO Country Codes |
| UPOD | Under Promise, Over Deliver | - | ISO Country Codes |
| UR | You Are | - | ISO Country Codes |
| UR2K | You Are Too Kind | - | ISO Country Codes |
| URAPITA | You Are A Pain In The Ass | - | ISO Country Codes |
| URSAI | You Are Such An Idiot | - | ISO Country Codes |
| URT1 | You Are The One | - | ISO Country Codes |
| URW | You Are Welcome | - | ISO Country Codes |
| URWS | You Are Wise | - | ISO Country Codes |
| URYY4M | You Are Too Wise For Me | - | ISO Country Codes |
| US | Utter Sh*t | - | ISO Country Codes |
| US | You Suck | - | ISO Country Codes |
| USP | Unique Selling Proposition | - | ISO Country Codes |
| UTM | You Tell Me | - | ISO Country Codes |
| UV | Unpleasant Visual | - | ISO Country Codes |
| UWIWU | You Wish I Was You | - | ISO Country Codes |
