QRZ, the name of the website, is the "Q" code for "Who is calling me?" and corresponds to the site's purpose of assisting amateur radio operators with the lookup of ham radio call signs from every country in the world.

QRZ was founded in 1992 by Fred Lloyd, AA7BQ as a spinoff of what was once called the "Callsign Project", a cooperative effort designed to obtain and distribute FCC database tapes. The "Callsign Project" was born on the internet newsgroup rec.

I'm new to HF and have a question about QSO conversations with "QR Zed" and "QSL". It seems to me the meaning of QRZ has somewhat changed over time. It's my understanding that QRZ means "who is calling me" and QSL means "can you acknowledge."

The term “QSL” comes from the international Q code and means “I confirm receipt of your transmission”. A QSL card is therefore a written confirmation. The sending of QSL cards dates back to the 1920s when AM radio broadcasts were still a novelty and stations wanted to know how far away they were being received.