| Y | Why? | - | ISO Country Codes |
| Y! | Typical Man | - | ISO Country Codes |
| YA | Yet Another | - | ISO Country Codes |
| YABA | Yet Another Bloody Acronym | - | ISO Country Codes |
| YACC | Yet Another Calendar Company | - | ISO Country Codes |
| YAFIYGI | You Asked For It You Got It | - | ISO Country Codes |
| YAOTM | Yet Another Off Topic Message | - | ISO Country Codes |
| YAUN | Yet Another Unix Nerd | - | ISO Country Codes |
| YBF | You've Been F*cked | - | ISO Country Codes |
| YBS | You'll Be Sorry | - | ISO Country Codes |
| YBY | Yeah Baby Yeah | - | ISO Country Codes |
| YBYSA | You Bet Your Sweet Ass | - | ISO Country Codes |
| YCT | Your Comment To | - | ISO Country Codes |
| YDKM | You Don't Know Me | - | ISO Country Codes |
| YGBK | You Gotta Be Kidding | - | ISO Country Codes |
| YGBSM | You Gotta Be Sh*tting Me | - | ISO Country Codes |
| YGLT | You're Gonna Love This | - | ISO Country Codes |
| YGTBK | You've Got To Be Kidding | - | ISO Country Codes |
| YGWYPF | You Get What You Pay For | - | ISO Country Codes |
| YHM | You Have Mail | - | ISO Country Codes |
| YIC | Yours In Christ | - | ISO Country Codes |
| YIU | Yes, I Understand | - | ISO Country Codes |
| YIWGP | Yes, I Will Go Private | - | ISO Country Codes |
| YKW | You Know What | - | ISO Country Codes |
| YKWIM | You Know What I Mean | - | ISO Country Codes |
| YM | Your Mother | - | ISO Country Codes |
| YMAK | You May Already Know | - | ISO Country Codes |
| YMMV | Your Mileage May Vary | - | ISO Country Codes |
| YNK | You Never Know | - | ISO Country Codes |
| YOYO | You're On Your Own | - | ISO Country Codes |
| YR | Yeah Right | - | ISO Country Codes |
| YRYOCC | You're Running On Your Own Cuckoo Clock | - | ISO Country Codes |
| YS | You Stink(er) | - | ISO Country Codes |
| YSAN | You're Such A Nerd | - | ISO Country Codes |
| YSIC | Why Should I Care? | - | ISO Country Codes |
| YSK | You Should Know | - | ISO Country Codes |
| YSYD | Yeah, Sure You Do | - | ISO Country Codes |
| YTB | You're The Best | - | ISO Country Codes |
| YTRNW | Yeah That's Right, Now What? | - | ISO Country Codes |
| YTTT | You Telling The Truth | - | ISO Country Codes |
| YUPPIES | Young Urban Professionals | - | ISO Country Codes |
| YW | You're Welcome | - | ISO Country Codes |
| YWIA | You're Welcome In Advance | - | ISO Country Codes |
| YY4U | Too Wise For You | - | ISO Country Codes |
| YYSSW | Yeah Yeah Sure Sure Whatever | - | ISO Country Codes |
