If at dialogue on the Internet all users use nicknames radio fans identify themselves with the help of system of identification signals - so-called signal. Signal are appropriated to all radio stations: broadcasting, coherent, amateur. Signal is "name" of radio station, and at radio fans - and a pseudonym of her owner. It is valid "nick" which you quite often use on the Internet, with that only a difference that similar nick is fixed legislatively in the sanction to work on air and to anybody to another to use given nick (signal) it is not authorized. Radio amateurs remember signal each other first of all. Yes differently also it is impossible: Mikes or Jones - thousand, and repeating signal is not present, everyone signal is unique.

   Signal can be different. At broadcasting radio stations is more often melodies, the musical fragments (jungles) sounding on air before the beginning of transfer, at radio stations of any objects - " words - symbols" (for example, "Iceberg", "Seagull"), at usual coherent - a combination of letters or letters and figures. Of letters and figures will consist also amateur signal.

   That on signal it was possible to define the country to which posesses radio station, under the international agreement to each country are allocated (it by the way International Radioamateur Union IARU) groups of initial signs signal is engaged. So, Russia letters UA … UI, RA … RZ and U0-U9 are allocated. All also begin with these signs signal amateur radio stations of Russia. And for an example some groups of initial signs on signal some countries:
UR or US - Ukraine, DA - Germany, I or IC - Italy, F - France,
VK - Australia, JA - Japan, NB or WA - the USA, SP or SR - Poland,
5V - That, 6Y - Jamaica, OM - Slovakia, 5B - Cyprus …

   The full list the list of distribution of blocks signal on the countries is resulted here.

   Signal amateur radio stations are under construction under the, special laws. First of all, in the middle amateur signal there is a figure, for example: RV3ABM or SP2DX. The first part signal - Radio Amateurs name her prefix - frequently allows to define and area of the country in which there is a radio station. So, territories of Russia, Poland, Hungary, Canada, Brazil, the USA and the majority of other countries are divided into conditional radioamateur areas. Therefore, having heard, we admit, signal SP5AD at once it is possible to tell, that this radio station is in Poland, in Warsaw (the fifth radioamateur area). Certainly, this system is very convenient for radio amateurs. Nevertheless in some countries it is not accepted. On prefixes signal operators some countries it is possible unless to define only, whether the beginner the owner of this signal or the skilled radio fan as there signal are given out successively, without taking into account a territorial belonging.

   On a prefix signal some countries to define, whether the radio station belongs to one person (radio station of individual using) or club, collective (shared radio station). In Sweden, for example, collective stations have prefixes with letters SK, whereas individual - with SM, etc. Quite often on a prefix it is possible to judge qualification of the owner of radio station. So, in Israel to beginners give out signal with letters 4Z7.