A database of current amateur radio call signs is available at QRZ.com and at HamCall.net. Each site features a searchable database along with amateur radio equipment that owners list for trade or sale. The sites also provide member support and serve as forums for amateur radio enthusiasts.
A call sign is a unique identifier of a transmitting station, often assigned by a government body and expressed as a combination of letters and numbers. In the case of U.S. amateur radio activity, the Federal Communications Commission licenses call signs and sometimes assigns them to operators as well as to stations. The call sign database controls the distribution of call signs and helps radio operators identify the call sign of the operator with whom they wish to communicate.