Q-signals are codes abbreviating a detailed question or answer. The codes, as agreed upon by the International Telecommunication Union, are used worldwide on radiotelegraph.
Q-signal abbreviations are given the form of a question when followed by a question mark. When an abbreviation is used as a question and is followed by additional or complementary information, the question mark should follow this information.
QRZ? QRZ? - means, "who is calling?"
Written by: NJ2X, Michael Maher