| Abbreviation | Definition |
|---|---|
| XMSN | Transmission |
| XMTR | Transmitter |
| XO | Hugs & Kisses |
| XQO | Crystal Quartz Oscillator |
| XYF | Ex-Wife |
| XYL | Wife |
| YARC | Yavapai Amateur Radio Club |
| YARC | Yonkers Amateur Radio Club |
| YARM | Yet Another Radio Module |
| YB | Young Boy |
| YDX | Yankee Delta Xray |
| YF | Young Friend |
| YI | You In? |
| YL | Young Lady |
| YSRC | Young Stars Radio Club |
| YW | You're Welcome |
| YWK | Long Wave Beacon, 184.320 kHz |
| ZBZ? | Can You Read Me? |
| ZCQ | Mahe, Seychelles Islands, radio station |
| ZDK | Re-transmission of a Message |