Study — Q-Codes

QRT   --.-/.-./-          # "suspending operation"
QRZ   --.-/.-./--..       # "who is calling?"
QRL   --.-/.-./.-..       # "are you busy?", "I am busy"
QRM   --.-/.-./--         # "man made interference"
QRN   --.-/.-./-.         # "static interference"
QRX   --.-/.-./-..-       # "will call again in X minutes"

QSL   --.-/.../.-..       # "can you acknowledge receipt?"
QSK   --.-/.../-.-        # "full break mode?"
QSO   --.-/.../---        # "can you communicate with _ directly?"
QSP   --.-/.../.--.       # "will you relay a message to _?"
QSR   --.-/.../.-.        # "please repeat call"
QSS   --.-/.../...        # "what working frequency?"
QST   --.-/.../-          # "broadcast message to all amateurs"
QSU   --.-/.../..-        # "shall I send/reply on freq _?"
QSW   --.-/.../.--        # "will you send on freq _?"
QSY   --.-/.../-.--       # "change freq to _"
QSB   --.-/.../-...       # "signal fading" (signal strength variation)

QTH   --.-/-/....         # "location"