Morse code required for the privilege to use the HF bands. Until 2000, proficiency at the 20 wpm level was required to receive the highest level of amateur license (Amateur Extra Class); effective April 15, 2000, the FCC reduced the Extra Class requirement to five wpm. Finally, effective on February 23, 2007, the FCC eliminated the Morse code proficiency requirements from all amateur radio licenses. While voice and data transmissions are limited to specific amateur radio bands under U.S. rules, Morse code is permitted on all amateur bands—LF, MF, HF, VHF, and UHF. In some countries, certain portions of the amateur radio
Morse code and Mediterranean Sea) traffic was in 'dotty' or 'dashy' Morse during the entire war. In popular culture, this is mostly remembered in the book "The Codebreakers" by Kahn and in the national archives of the UK and Australia (whose SIGINT operators copied most of this Morse variant). Kahn's cited sources come from the popular press and wireless magazines of the time. Other forms of 'Fractional Morse' or 'Fractionated Morse' have emerged. Decoding software for Morse code ranges from software-defined wide-band radio receivers coupled to the Reverse Beacon Network, which decodes signals and detects CQ messages on ham bands, to smartphone