The emission of radio frequency shall be identified using identification signals or other methods.
The aforesaid identification signals must not be easily misunderstood or mistaken.

Identification signal shall be a call sign, maritime mobile service identity or other recognizable identification methods.
Maritime mobile service identity (MMSI), which is a series of digits designed for maritime mobile services and maritime mobile-satellite services as prescribed in ITU Radio Regulations, is sent to uniquely identify ship stations, ship earth stations, coast stations, coast earth stations or other stations.
The recognizable identification methods provided in Paragraph 1 may be one or more of the following: station name, station location, operation agency, official registration mark, the flight identification number, selective calling number or signal, the selective calling identification number or signal, the characteristic signals, the characteristic of the emission or other clearly distinguishing features readily recognized internationally.

The user shall transmit identification signals in one of the following formats:
1. Speech, using simple amplitude or frequency modulation;
2. International Morse code transmitted at manual speed;
3. A telegraph code compatible with conventional printing equipment;
4. By using any other format recommended by International Telecommunications Union.

Identification signals shall be automatically transmitted unless otherwise specified by laws.

The emission of the following radio frequency shall carry identification signals:
1. Amateur radio;
2. Radio and TV broadcast;
3. Relay stations with a bandwidth below 28 MHz;
4. Mobile communications;
5. Standard frequency and time signal;
6. Radio beacon station.

The emission of satellite emergency position-indicating radio beacon shall carry identification signals.
The aforesaid satellite emergency position-indicating radio beacon uses digital selective calling technology, or frequency between 406 MHz and 406.1 MHz and between 1.6455 GHz and 1.6465 GHz.

In regard to the transmission of identification signals, the transmission of identification signals must be undertaken at least once every hour and within five minutes before or after each hour. Where the said transmission results in an unreasonable interruption of communications, it shall be undertaken at the beginning and at the end of the transmission.
The transmission rules as prescribed in the preceding Paragraph shall be applied mutatis mutandis to the test, adjustment or experiment.

Where a number of stations work simultaneously in a common circuit, each station shall, either as relay stations or in parallel on different frequencies, transmit its own identification signal or identification signals of all stations that work in the common circuit.

All ship and ship earth stations for maritime communications and maritime satellite communications, as well as coast or coast earth stations with which they communicate shall adopt maritime mobile service identify as their identification signals.

The allocation of identified maritime radiocommunications, a station which can be identified with other methods, or those whose transmission characteristics have been published in an international document may be exempted from “Table of Allocation of International Call Sign Series”.

Where a fixed station uses more than two radio frequencies, each radio frequency may use the identification signal of that frequency.

Where a broadcasting station uses more than two radio frequencies, each radio frequency may use the call sign used solely for this frequency, or adopt an appropriate identification method, such as reporting its location and used radio frequency.

Where a land station uses more than two radio frequencies, each frequency may use its respective identification signal.

In principle, coast stations shall use the same call sign to each frequency series.

The allocation of the call sign shall be made in accordance with the Allocation Table of the Call Sign of Radio Stations as established by the competent authority after considering the International Radio Regulations, and shall use the following three parts:
1. BAA-BZZ
2. XSA-XSZ
3. 3HA-3UZ

Call signs shall be composed of English letters and Arabic numbers. The first two characters of international call sign series shall be two English letters; one letter and one Arabic number; or one Arabic number followed by one English letter.
The composition of call signs shall adhere to the following rules. Combinations that can potentially be confused with distress signals or signals of the same nature, or combinations that leave radio communications messages shall not be used:
1. Land and fixed stations: the first two characters shall be followed by one letter, or the first two characters shall be followed by one letter and then no more than three digits. Fixed communications shall, in principle, have two characters followed by one letter and then two digits.
2. Ship stations: the first two characters shall be followed by two letters; the first two characters shall be followed by two letters and then one digit; the first two characters (should the second character be a letter) shall be followed by four digits; or the first two characters shall be followed by one letter and then four digits.
3. Aircraft stations: the first two letters shall be followed by three letters.
4. Ship survival craft stations: the call sign of carrier ship shall end with two digits.
5. Emergency position-indicating radio beacon stations: shall use the Morse letter B or call sign of the carrier ship, on which the radio beacon station is located.
6. Aircraft rescue stations: the full call sign of mother aircraft followed by one digit.
7. Land mobile stations: the first two characters (should the second character be a letter) followed by four digits, or the first two characters followed by one or two letters and then four digits
8. Test stations:
a. One character (B, F, G, I, K, M, N, R or W) followed by one digit (except 0 and 1) and then a series of no more than four characters, where the last character must be a letter; or two characters followed by one digit (except 0 and 1) and then a series of no more than four characters, where the last character must be a letter.
b. In special cases, the competent authority may, for the purpose of temporary use, provide a call sign of less than four digits in according to the preceding item.
9. Space service stations: the first two characters followed by two or three digits.
The first digit following the letter as prescribed in the preceding paragraphs shall not include 0 and 1.

The call signs of international public communications, amateur radio communications and other radio communications which are capable of causing harmful interference beyond the boundaries of the territory or geographical area in which they are located, shall have call signs from the international series in accordance with “Table of Allocation of International Call Sign Series” of ITU Radio Regulations.

The use of voice radio communications shall be identified in accordance with the following rules.
1. Coast stations: the call sign or geological location of coast station followed by the word “RADIO” or other appropriate identification.
2. Ship stations: the call sign or the vessel’s official name may, under the circumstances of not being mixed up with distress, emergency and safety signals, be added to the vessel’s owner or company name, or its selective calling number of signal whenever necessary.
3. Ship survival craft stations: the identification signals formed by the call sign or the carrier ship’s name shall be followed by two digits.
4. Emergency position-indicating radio beacon stations: name or call sign of the carri-er ship.
5. Aeronautical stations: name of the airport or its geological location. Whenever necessary, it may be followed by appropriate characters that indicate the communications mission.
6. Aircraft stations: call sign, by which the name of aircraft owner or type may be followed; characters that are identical with the aircraft’s official registration identification; or characters that indicate the airline’s name followed by flight identification number.
7. Aircraft survival stations: call sign.
8. Base stations: call sign, or the name of its geological location. Whenever necessary, it may be followed by other appropriate identifications.
9. Land mobile stations: call sign, or the identification of the vehicle or any other suitable identification.
10. Test stations: call sign.
The language used for identification as referred in the preceding paragraph must be clear; Mandarin shall be used for domestic communications.

Where selective calling equipment is used in maritime communications, selective calling number composed of Arabic numbers must be used. The composition of call signs and identification numbers of coast stations are as follows:
1. The identification number of coast station shall be composed of four digits and shall not start with two zeros (“00”).
2. Selective calling identification number of ship station shall be composed of five digits.
3. Predetermined group of ship stations shall be composed of five digits: one digit that has been repeated five times or two different digits repeated alternately.

The assignment of selective calling identification numbers of ship stations and identification number of coast stations shall accord with the following rules:
1. Selective calling identification number of ship stations and identification number of coast stations shall be used in maritime communications.
2. When the selective calling system conforms to the selective calling system of international maritime mobile service of Radio Regulations of the International Telecommunication Union, the selective calling number and the coast station identification number shall be selected from the allocated international series numbers and allocate them to the ship station and coast station.
3. Selective calling identification numbers of ship station shall be set in narrow-band printing equipment.