![CQ](https://www.xwhos.com/photo/whois_cq_profile_1189027.webp)
CQ
CQ is a code used by wireless operators, particularly those communicating in Morse code, but also by voice operators, to make a general call. Transmitting the letters CQ on a particular radio frequency is an invitation for any operators listening on that frequency to respond. It is still widely used in amateur radio.