Q Codes / Informal
| QRA | Name |
| QRB | Distance |
| QRG | Frequency |
| QRK | Intelligibility |
| QRL | Busy |
| QRM | Interference |
| QRN | Noise |
| QRO | High power |
| QRP | Low power |
| QRQ | High speed CW |
| QRS | Low speed CW |
| QRSS | Very low speed CW |
| QRT | Shut down the station |
| QRV | Ready |
| QRX | Stand by |
| QRZ? | Who is calling me? |
| QSB | Fading |
| QSD | Defective keying |
| QSK | Break in |
| QSL | Confirmation or card to confirm contact |
| QSO | Radio contact |
| QSY | Change frequency |
| QTC | Message |
| QTH | Location |
| QTR | Time |