Q-codes -- Popular Q codes in amateur radio -- Z-codes -- Popular Z-codes in amateur radio -- ITU callsign groups -- ITU country codes -- International broadcast stations codes -- International news agencies codes -- Common abbreviation in radio communications -- Popular abbreviations in amateur radio -- Amateur radio procedural signals -- Common prosigns in RTTY mode -- HX procedural signals in radio telegraphy -- Operating mode coding system -- The RST system -- ITU recommended phonetics -- ITU frequency band allocations 30 MHz to 400 GHz -- Morse & TTY codes

In the world of telecommunication, be it in the area of amateur or professional applications, a system of codes and abbreviations is widely used. This coding or abbreviation habit is however not a product of coding hype or fad but is a necessity.