WARC bands

The WARC bands are three portions of the shortwave radio spectrum used by licensed and/or certified amateur radio operators. They consist of 30 meters (10.100–10.150 MHz), 17 meters (18.068–18.168 MHz) and 12 meters (24.890–24.990 MHz). They were named after the World Administrative Radio Conference, which in 1979 created a worldwide allocation of these bands for amateur use. The bands were opened for use in the early 1980s. Due to their relatively small bandwidth of 100 kHz or less, there is a sort of gentlemen's agreement that the WARC bands may not be used for general contesting. This agreement has been codified in official recommendations, such as the IARU Region 1 HF Manager's Handbook, which states:

Contest activity shall not take place on the 10, 18 and 24 MHz bands.

Throughout most of the world, the 30 meter band cannot be used for phone communications except in emergency situations. However, part of Region 1 (Africa, south of the equator, during daylight hours) is permitted to use phone. The USA limits amateur radio users to 200 watts peak envelope power on this band.