The Q Code came into being internationally in 1912 to overcome the language problems involved in communications by radio among ships and shore stations of all countries. The original list of fifty three-character "Q" codes adopted by international agreement contain many which are still used by Ham operators.
In addition to being language independent, they provide more compact communications (once learned) especially when communicating in Morse Code (the mode radio operators call "CW" (for "continuous wave")). While not as popular today as in the past, CW is a very enjoyable mode that many Hams enjoy exclusively.
For example in CW, you could say, "I'm located in Atlanta Georgia" but it's more compact to say, "QTH Atlanta GA".
Or, "I'm having difficulty hearing you because of static" becomes simply "QRN".
Or, "Can you confirm this transmission?" because "QSL?".
If used with a question mark, the Q Code is a question; if not, a response.
Here's the list of the most common Q Codes in use today by Ham operators:
| Q Code | Meaning |
| QRM | Is my transmission being interfered with? Your transmission is being interfered with |
| QRN | Are you troubled by static? I am troubled by static |
| QRO | Shall I increase power? Increase power. |
| QRP | Shall I decrease power? Decrease power. |
| QRQ | Shall I send faster? Send faster |
| QRS | Shall I send more slowly? Send more slowly |
| QRT | Shall I stop sending? Stop sending. |
| QRV | Are you ready? I am ready. |
| QRX | Stand by |
| QRZ | Who is calling me? |
| QSB | Are my signals fading? Your signals are fading. |
| QSL | Can you acknowledge receipt? I am acknowledging receipt. |
| QSO | A contact |
| QSY | Shall I change to another frequency? Change to another frequency. |
| QTH | What is your location? My location is ___. |
