"QSL" means "received" or "receipt given" in the Q abbreviation used for communication. The "QSL" card is a unique certificate for amateur radio stations to confirm contact or listening, so each radio station should have its own QSL card. All enthusiasts regard it as their unremitting pursuit goal to get as many cards sent from different countries and regions as possible. Applications for all internationally awarded amateur radio certificates must be based on QSL cards. Many important international amateur radio competitions also use the received QSL cards as the basis for evaluation. In my country, receiving a certain number of QSL cards is considered as an individual One of the necessary conditions for obtaining the higher-level "Operation Certificate". Therefore, every fan is obliged to send his or her QSL card to the other party in time.