WARC bands

The World Administrative Radio Conference (WARC) bands consist of three portions of the shortwave radio spectrum allocated for amateur radio use: 30 meters (10.1–10.15 MHz), 17 meters (18.068–18.168 MHz), and 12 meters (24.89–24.99 MHz). These bands were established by the World Administrative Radio Conference in 1979 and opened for use in the early 1980s. Due to their narrow bandwidth of 100 kHz or less, there is a gentlemen's agreement that contesting should not occur on these bands, as codified in official recommendations such as the IARU Region 1 HF Manager's Handbook.

The 12-meter band plan varies by region. In Canada and the United States (Region 2), Radio Amateurs of Canada provides recommendations for usage. Similar regional variations exist for the 17-meter and 30-meter bands. For the 30-meter band, most of the world restricts voice communications except in specific cases, such as emergencies or limited use in Africa south of the equator during daylight. In Region 2, the U.S. limits amateur radio users to 200 watts peak envelope power on this band.

In Australia (Region 3), advanced license holders can use voice operation on a portion of the 30-meter band, while digital modes are restricted to 10.13–10.15 MHz. Japan also has specific restrictions, requiring occupied bandwidths of less than 2 kHz. These allocations and usage guidelines are coordinated by regional bodies like IARU and national organizations such as Radio Amateurs of Canada and the Federal Communications Commission in the U.S.