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Amateur radio call signs

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The International Telecommunication Union (ITU) allocates call sign prefixes for radio and television stations of all types. Amateur radio operators have since 1927 been allocated unique call letters (call sign) to uniquely identify them, as well as locate then within a geographical region of the world - usually a country.

Prefixes are assigned internationally, and a separating numeral plus suffix are added by a national body to produce this unique identifier. These prefixes are agreed upon internationally, and are a form of country code. Each country must only assign call signs to its nationals or operators under its jurisdiction that begin with the characters allocated for use in that country or its territories.

Call signs meant for amateur radio follow the ITU's Article 19, specifically 19.68 and 19.69.[1]

Formation of an amateur radio call sign

An amateur operator's call sign is composed of a prefix, a separating numeral and a suffix.

The prefix can be composed of letters or numbers, the separating numeral is one from Ø to 9, and a suffix is from one to four characters where the last one has to be a letter.

Examples of call signs and their constituent parts are as follows:

Call Sign Prefix (within ITU assigned range) Separating numeral Suffix format type
K4X K 4 X 1x1 call sign, usually time limited special event (USA)
B2AA B 2 AA 1x2 call sign (China)
A22A A2 2 A 2x1 call sign (Botswana)
I2ØØØØX I 2 ØØØØX 1x5 call sign, special event (Italy)
4X4AAA 4X 4 AAA 2x3 call sign (Israel)
3DAØRS 3DA Ø RS 3x2 call sign (Swaziland)

Call signs begin with a one- two- or three-character prefix chosen from a range assigned by the ITU to the amateur's country of operation or other internationally recognized jurisdiction. This is not necessary always the amateur's country of citizenship. An individual operator is assigned a unique call sign beginning with this prefix and then completed with a separating numeral and suffix.[2]

The beginning of the list of call sign ranges is:

    • AAA-ALZ United States of America
    • AMA-AOZ Spain
    • APA-ASZ Pakistan (Islamic Republic of)
    • ATA-AWZ India (Republic of)
    • AXA-AXZ Australia
    • AYA-AZZ Argentine Republic
    • A2A-A2Z Botswana (Republic of)
    • A3A-A3Z Tonga (Kingdom of)
    • A4A-A4Z Oman (Sultanate of)

(concludes with....)

    • 9VA-9VZ Singapore (Republic of)
    • 9WA-9WZ Malaysia
    • 9XA-9XZ Rwandese Republic
    • 9YA-9ZZ Trinidad and Tobago

A unique international prefix

Beginning at the left of the call sign block, the country chooses one, two or three characters from within the range assigned by the ITU, enough to distinguish its call signs from other jurisdictions.

A "letter range" always first refers to the first letter of a block, meaning that in the letter range "AAA-ALZ", the "A" is the letter range-designator.

Factors for a country to consider when choosing within its assigned range:

  • When a 1-letter prefix is enough - This is only possible when the whole letter range is assigned to one jurisdiction. For example KAA-KZZ is assigned to the United States. The U.S. Federal Communications Commission (FCC) (the American national body) can assign a single letter `K` prefix as the US is assigned the whole 'K' block. As numbers warrant the US can also assign prefixes 'KA', 'KB', 'KC' and so forth as needed. A single-letter prefix is also possible for block ranges beginning with B (China), F (France), G (United Kingdom), I (Italy), K (USA), M (UK), N (USA), R (Russia) or W (USA) as each are also assigned by the ITU to single jurisdictions
    • When assigning from the KAA-KZZ block, the FCC could assign three letter prefixes (e.g. KAA, KAB, KAC, etc.) but this produces cumbersome call signs, and one- and two-letter prefixes produce more than enough than needed as it is.
    • None of the B, F, G, I, K, M, N, R, and W ranges are issued with a numeral as a second character, so the first digit in a call in those ranges is always the separating numeral.
  • When 2-characters are needed - Two character prefixes are needed when the letter range is divided among two or more jurisdictions. For instance, AAA-ALZ is assigned to the USA; but Spain, Pakistan, India and Australia are assigned other portions of the 'A' block, so at least two characters from the left need to be assigned by each country to produce unique call signs. Letter-number prefixes 'A2' through 'A9' are also assigned to eight other jurisdictions, so a callsign prefix with a single 'A' does not uniquely distinguish any of them.
    • Korea has issued a special event callsign of D9K.[3] Technically, the 'D9' is the ITU prefix for South Korea, so they have issued a call with no separating numeral. This could cause confusion if other countries in the 'D' block started issuing single-character prefixes with '9' as the separating numeral. For example, Germany is assigned DAA-DRZ and if they issued an out-of-format call of D9K as well (with the 9 as the separating numeral) this would produce call-sign confusion.
    • Bahamas issues call signs without a separating numeral. They are assigned the C6A-C6Z block, and the '6' is part of the 2-character prefix. Examples are as found on QRZ.COM (C6AFO, C6AGB, etc.).
    • Cyprus has issued H2T[4] as a special event call sign. Whereas Cyprus is assigned the H2A-H2Z block, there is then no numeral separator, just a one-letter suffix.
  • When a 3-character prefix is needed - This is an unsusal situation and occurs with callsigs in the 3DA-3DZ block range. Fiji and Swaziland are assigned 3DN-3DZ and 3DA-3DM respectively, so they should choose also the third character from the left to produce unique call signs, but in practise do not.
    • Fiji has issued many call signs with a '3D' prefix and a '2' numeral separator. In theory this does not distinguish their call signs from Swaziland which is issued the 3DA-3DM block.
  • Jurisdictions frequently adopt one or only a few of the prefixes allowed to them within a block-range, reserving the others for other occasions. Canada has 24 possible, two-letter prefixes from its assigned ranges, but only assigns CY, VA, VE, VO, and VY for normal operation.

A unique internal numeral and suffix

The jurisdiction then assigns a single digit (a numeral to separate prefix from suffix) as well as a suffix of from 1 to four characters (the last being a letter) and appends them in that order to their assigned prefix(es). The resulting call sign must uniquely identify a ham radio operator within that jurisdiction.

Sometimes the prefix plus separating numeral is together referred to as the prefix.

This produces internationally recognized, unique call signs to identify licensed operators.

General formats

In general an amateur radio callsign is of one of these forms where:

  • P - prefix character (letter or numeral, subject to exclusions below). Prefixes can be formed using one-letter, two-letters, a digit and a letter, a letter and a digit, or in rare cases a digit and two letters. There is no ITU allocation of digit-only prefixes. Letter-digit-letter prefixes are possible but there are no known cases of them being issued by national bodies.
  • N - a single numeral which separates prefix from suffix (any digit from Ø to 9). Often a cross-hatched Ø is used for the numeral zero to distinguish it from the letter O.
  • S - suffix character (letter or numeral, last character must be a letter). Digits are in practise used sparingly in suffixes and almost always for special events. This avoids confusion with separating numerals and digits in prefixes in regularly issued call signs.

Call signs almost always have one of the following forms:

  • PNS, 1x1 call sign
    • usually for a special event, the prefix is always a single letter character, as is the suffix. Can only be assigned in the B, F, G, I, K, M, N, R or W prefix range. (See discussion on the D9K call sign issued by Korea above - 'when 2 charachers are needed'.)
  • PPNS, 2x1 call sign
    • prefix can be letter-letter, letter-digit, or digit-letter. A call sign composed of a letter, two digits, and one-letter is always a 2x1 call sign, meaning it has a letter-digit prefix and a single-letter suffix.
    • for all letter-digit-digit-letter callsigns, if the first character is other than B, F, G, I, K, M, N, R or W then it is a 2x1 call sign
  • PNSS, 1x2 call sign
    • prefix always a letter, suffix almost always two letters to avoid confusion with 2x1 call signs.
    • As a precaution, the ITU has issued no prefixes in the B, F, G, I, K, M, N, R or W block ranges with letter-number possibilities, meaning that the first digit would have to be the separating numeral anyway.
    • for all letter-digit-digit-letter callsigns, if the first character is B, F, G, I, K, M, N, R or W then it is a 1x2 call sign
  • PNSSS, 1x3 call sign
    • these have the same precautions as 1x2 call signs to prevent confusion with 2x2 format
  • PPNSS, 2x2 call sign
    • these have the same precautions as 2x1 call signs to prevent confusion with 1x3 format
    • confusion might seem to arise with letter-digit-digit-digit-letter call signs, however in that case the second digit would be the numeral separator. (see 2x1 above)
  • PPNSSS, 2x3 call sign
    • by far the most common format
  • PPNSSSS, 2x4 call sign, or more
    • four-character suffix (or more) assigned by some countries (e.g. Australia to designate operator class), or 5 or more characters for special events. In New Zealand the first character of the SSSS suffix is sometimes a digit for special events
  • PPPNSS or PPPNSSS, 3x2, 3x3 or more...
    • assigned when two characters of the prefix are not enough to distinguish jurisdiction (eq. Fiji 3DN-3DZ and Swaziland 3DA-3DM)

Suffix assignment

Since suffixes can also contain digits, some countries issue suffixes (usually temporarily) beginning with enough digits to produce a number, usually associated with the special event (e.g. the number of years, see New Zealand below).

In normal call sign assignment, if a call sign has two digits (e.g. S59DSC or 2S4LGR - PPNSSS), the first digit is almost always a prefix character (e.g. S5 indicating Slovenia, or 2S indicating Scotland).

Call signs with more than one digit

Call signs with two (or more) digits in them can arise a number of ways. When the digits abut one another, it is important to distinguish which digit belongs to the prefix, which is the separating numeral, and which may belong to the suffix.

In every case (Bahamas being an exception), a jurisdiction assigned a letter-digit prefix by the ITU will have a second digit as their internally assigned prefix/suffix separator. An example is A33A, a Tongan call sign; the first '3' is the second character of the prefix and the second '3' is the numeral separating 'A3' from the single-letter suffix 'A'. There are no single letter prefixes allocated by the ITU with an 'A', so the first 3 must be part of the prefix.

Neither New Zealand's nor the Republic of Ireland's prefixes have numerals as prefix-characters. However, both allow a second numeral as the leading character of the suffix and is not to be confused with the sign's separating numeral. As the first character of the suffix, the two digits can be taken together; for instance, to represent a two-digit number of significance to the operator.

A New Zealand amateur who has been active for 30 years and currently is assigned call sign ZL1xxx can operate as ZL3Øxxx for up to three months.[5] Technically, the '3' is the separating numeral and the 'Ø' is the first character of the suffix.

Similarly a club with call ZL4xxx which has been established for 23 years can operate as ZL23xxx for up to three months.

The New Zealand operator substitutes their identifying separating numeral with another, so long as a second digit is added to the beginning of their normal suffix. This may result in call sign confusion in the rare case of two amateurs in differing numeral-areas also both having the same number of years of operation and suffix.

Ireland also takes advantage of the ITU standard to allow digits as suffix-characters. The Irish Radio Transmitters Society operates as EI75IRTS celebrating 75 Years of incorporation - 1932-2007.[6]

Ofcom in Great Britain also allows numerals in special event call signs. For instance GB75RD was a special event sign for the 75th anniversary of the Reading and District Amateur radio club.[7]

Exclusions

The 26 letters of the English alphabet and ten digits may be used to form call signs, accented letters excluded.

Letter combinations which can be confused with distress calls or which are reserved as abbreviations for radiocommunications services are excluded (e.g. Q codes).[8] The ITU Article 19 exclusions are those found in ITU-R M.1172.[9] In practise, no prefix begins with a the letter 'Q', but 'Q' can be the second letter (eq. Malawi assigned the 7QA-7QZ block).

Double- or single-digit prefixes are excluded. A callsign with a leading digit in the prefix always has a second character which is a letter and in rare cases a third character which is also a letter.

Currently, no allocated prefix has Ø (zero) or 1 (one) as one of its characters as they can be confused with the letters O (Oscar) and I (India).

All ten digits from Ø to 9 are allowed to be used as a separating numeral at the discretion of national allocating bodies.

Secondary prefix or suffix types

Ancillary prefixes or suffixes further identify the location and/or operating condition of an amateur operator.

According to the Canada/United States Operating Agreement treaty[10] amateurs from one country operating in the other sign with their home call sign, but attach the call area prefix where they are operating to their call. For instance, an amateur from British Columbia (VE7 in Canada) operating in Washington State (W7 in the USA) would amend their home-call with a trailing /W7 (e.g. VE7xxx becomes VE7xxx/W7).

British amateurs operating as a visitor in CEPT countries are required to append the appropriate host country's prefix before their British call sign.[11] For instance an amateur holding a call of G3xxx operating in France would sign as F/G3xxx.

When a country's separating numeral denotes a geographic area within, an operator from one region operating in another region can affix a secondary suffix indicating so. For instance an amateur from Queensland, Australia, operating in Tasmania can sign as VK4xxx/7 or VK4xxx/VK7.

Other secondary operating suffixes can be attached - such as /P (for portable operation), /QRP (for operation at or below 5 watts), /M (for mobile operation), /AM (aeronautical mobile) or /MM (maritime mobile).

Some repeaters have automatic call sign transmission at regular intervals and use the secondary suffix /R at the call sign's end. Some jurisdictions discourage this practise on the grounds that it could be confused with an amateur from the repeater's location working portable in Russia.

Ancillary Prefix Usage notes:
/<digit> VE7xxx/7 denotes operator in his/her own call area operating away from primary location
/P VE7xxx/P denotes operator in his/her own call area operating away from primary location, on portable power
/<call area> VE7xxx/6, VE7xxx/VE6 denotes operator in another call area operating away from primary location, but within national boundary
/<call area> VE7xxx/W7 denotes operator in another call area operating away from primary location, but outside of national boundary
<call area>/ F/G3xxx UK operator operating in France
/QRP VE7xxx/QRP denotes operator running low power, usually less than 5 watts
/M VE7xxx/M denotes operator in a mobilesetting
/MM VE7xxx/MM denotes operator in marine mobile setting
/AM VE7xxx/AM denotes operator in aeronautical mobile setting

Callsigns within a country

General issuing practises

Each national authority has some options in relation to the form of the prefix, as long as enough characters are selected starting from the left of their assigned block to produce a prefix unique to its jurisdiction.

Each country has authority over which numeral separates the prefix and suffix. The prohibition of the use of the digits Ø and 1 in land mobile stations does not apply to amateur stations. The ITU however does not issue prefixes with either a Ø or 1 as one of the characters.

Bahamas issues call signs without a separating numeral. They are assigned the C6A-C6Z block, and the '6' is part of the prefix. Examples are as found on QRZ.COM (C6AFO, C6AGB, etc.).

The suffix can be from one to four characters subject to ITU exclusions (above).[8] On special occasions, for temporary use, administrations may authorize use of call signs with more than four suffix-characters.

Allocation options within a country

Whereas for ITU purposes the prefix does not include the separating numeral, for country purposes often the separating numeral is included when the prefix is referred to. Thus for Canada VE6 or VA6 are the prefixes for Alberta, while VE2 or VA2 are the prefixes denoting Quebec.

  • The most common suffix has three characters. The ITU only requires that the last suffix-character be a letter, but in practise suffixes are nearly always composed of letters. Australia requires its Foundation Class of operators to have a four-letter suffix.
  • Most countries select permanent or renewable calls from a narrow, specific range of possible assigned prefix alternatives. For instance The Philippines is allocated the DUZ-DZZ and 4DA-4IZ blocks - 12 possible two-character prefixes in all - but almost all Philippine amateur callsigns are issued with the DU prefix.
  • Some countries add or reserve an allowable second-character letter to the prefix to indicate the internal region of the operator - (e.g. G3xxx in England becomes GD3xx for the Isle of Man; or for KL6xxx, the L indicates Alaska).
  • Some countries reserve their separating numeral to indicate the internal region in which the individual operator resides (e.g. The United States: 6-California, 4-The Southeast, 3-Pennsylvania, Maryland, and Delaware).
  • Some countries reserve the first letter of the suffix to indicate the internal region in which the individual operator resides (e.g. Argentina assigns LU#N to Santiago del Estero where # is any numeral, or Russia where the separating numeral plus the first letter of the suffix denotes the Oblast of the call sign).
  • Some countries issue call signs meant for use in Antarctica (e.g. South Korea assigns HL8 to stations at its Antarctic base).
  • Canada is the only jurisdiction which issues a call sign prefix for use in International Waters - VEØ
  • Some countries reserve allowable prefixes to indicate the operating class of the amateur (e.g. China issues the BA prefix to 1st class operators).
  • Some countries limit 2- or 1-letter suffixes to operators with advanced privileges (e.g. The Republic of Georgia limits one-letter suffixes to “extra” class licenses).
  • Some countries reserve allowable prefixes for foreigners licensed in their jurisdiction (e.g. Japan reserves the 7J prefix for foreigners).
  • Malta reserves the 9H5 prefix for VHF-use and up.
  • Some countries reserve amateur radio prefixes for shortwave listeners (e.g. Germany reserves the DE prefix for SWLers. 'DE' is also a morse code abbreviation amateurs use meaning "from" when one station contacts another - e.g. VE7xxx de WB4xxx means, "calling station VE7xxx from my station of WB4xxx". Thus Germany has eliminated any potential confusion in the use of DE as a prefix as opposed to it as an abbreviation).
  • Belarus reserves some of its prefixes for WWII veterans.
  • Belarus reserves suffixes YAA-YZ for female operators.

Call sign oddities

  • Bahamas issues call signs without a separating numeral. They are assigned the C6A-C6Z block, and the '6' is part of the prefix. Examples are as found on QRZ.COM (C6AFO, C6AGB, etc.).
  • ALØHA - the Coconut Island DX Association in Hawaii (note: AL is a prefix reserved for Alaska)
  • M1AMI - from Colchester, England
  • GØRDO - someone named John in England
  • K1NKY - from New York
  • PA5TA - from The Netherlands
  • OH1O - from Finland
  • LA1ZY - someone in Norway who does not operate a lot
  • EI25SL is an Irish call sign used by "Welcome Slovenia to EU Special Event". The separating numeral is "2", and the "5" is the first character of the suffix. The Limerick Radio Club has operated as EI6ØLRC and EI7ØFOY.
  • Twelve character callsigns:
    • PAØ9MONUMENT - Netherlands, Dutch National Day of Monuments [12]
    • ON1ØØØNOTGER[13]
  • The Korean special event call 'D9K' technically has no separating numeral. This call is taken from the D7A-D9Z range assigned to the country by the ITU - the '9' is part of the prefix.[14]
  • the prefix 3CAK was issued to a Russian visiting Malabo, Equatorial Guinea, from January to April 2005. This also has no separating numeral.[15][16]

Prefix reassignment

As political boundaries change through treaty or warfare, sometimes call sign prefixes are reassigned by the ITU to the new controlling government, or are reassigned by national governments for other reasons.[17]

  • the block range VRA-VRZ (Hong Kong) was reassigned to China from Britain in 1999 following the end of the UK's lease over the territory.
  • VTZ-VZZ once was a range meant for use in the British Empire - now VTA-VWZ is assigned to India, VXA-VYZ to Canada, and VZA-VZZ to Australia. Because of the influence of Great Britain throughout the Mediterranean, Middle East and Pacific regions, there have been many call sign adjustments since WWII.
  • In 1947 the USSR was assigned the whole U-block (UAA-UZZ). Upon the USSR's break-up in 1991 the block was reassigned - UAA-UIZ (Russian Federation), UJA-UMZ (Uzbekistan), UNA-UQZ (Kazakhstan), and URA-UZZ (Ukraine).
  • prefix 8Z used to be used for the Iraq/Saudi Neutral Zone (8Z4) and the Kuwait/Saudi Neutral Zone (8Z5), both of which no longer exist so the prefixes were withdrawn.
  • San Marino dropped prefix 9A and M1 and was assigned T7.
  • Sikkim used to use AC3 (an American prefix) but when the country became a state of India in 1975 it adopted VU.
  • Timor used to use CR1Ø, but now uses an Indonesian prefix of YB9.
  • The Canal Zone in Panama used NY1, NY2, K4 or KZ5 when it was a territory of the United States, but now uses a Panama prefix based on HO or HP.
  • US Military personnel in Greenland used to use prefix KG1 and XP1, but now use OX.
  • Americans at Guantánamo Bay Naval Base used to use prefix NY4, now use KG4.
  • Territory of New Guinea used to use VK4 and now uses P2.
  • British Honduras used to use VP1 and now uses V3 as Belize.
  • VX9 used to designate both Sable Island (now CYØ) and St. Paul Island (now CY9) in Canada.
  • YZA-YZZ and 4N-4O used to belong to Yugoslavia before its break-up in 1992, Serbia is now YT-YU and other successor countries have their own prefixes.
  • Canada inherited Newfoundland and Labrador's respective prefixes of VO1 and VO2 in 1949 when Newfoundland and Labrador joined Canada. The Canadian government continues to assign those two prefixes to Newfoundland and Labrador.

Call signs used in unassigned ITU block ranges

Some call sign block ranges are unassigned by the ITU, e.g. the 1AA-1ZZ block. Any call sign used by an amateur in these unassigned block ranges usually had it assigned to them by a group with an unrecognized national claim.

DXCC Entities and IOTA

Amateur radio call sign prefixes almost always locate an operator within one of the 300+ DXCC entities in the world.

Any country or ITU prefix assignment can have many entities within it. For example in the United States Hawaii (with 'H' as the second character of the prefix and '6' as the separating numeral) and Alaska (with 'L' as the second letter of the prefix) are considered different DXCC entities, as are Sable Island and St. Paul Island in Canada.

The DX Century Club (DXCC) is an amateur radio operating award given by the American Radio Relay League to operators making contact with 100 or more geographic entities around the world. As such, the ARRL keeps a list of DXCC entities (not necessarily a country) for this purpose.[23] This list includes deleted entries and prefixes and the dates in which contacts with them will be counted towards the award.

The DXCC List is based upon Clinton B. DeSoto's landmark 1935 QST article defining a "country" as a discrete geographical entity.[24] A geographical portion of one country can be a separate DXCC entity if it is non-contiguous with or significantly distant from the main part of the national entity.

IOTA is a radio amateur abbreviation for Islands on the Air. It refers to a list of Islands worldwide maintained by the Radio Society of Great Britain, which assigns a unique code to an island or group of islands.[25]

Vanity Call Signs

Ham radio operators in the United States may pay a small fee and apply to get a specific callsign, including calls from other zones, so long as they have the appropriate license class for the desired callsign format. The callsign also must conform to the prefix standard assigned to that area. For instance, an Amateur Extra might have W0OL (which is a "1 x 2" call), but a General-class licensee could not, because 1 x 2 calls are reserved for the Amateur Extra class. Likewise, a ham on the mainland could not get a callsign beginning with the KH6 prefix, which is assigned to Hawaii.

There are a variety of reasons why someone would request a vanity callsign. Some people want a callsign that has their name or initials embedded in it. Some want a callsign that reflects a specific interest in amateur radio (like W7FM or K7ATV). Others request callsigns that were formerly held by family members or friends, or even callsigns that they themselves formerly held (and gave up for whatever reason). Some people want a callsign that is shorter, or easier to pronounce, or just "fits their personality" better. CW (Morse code) operators might want a callsign that "sounds good" or is short when sent in Morse. (This is referred to as "CW weight".) Since the FCC (in the US) does not restrict most requests (other than those submitted fraudulently), any of these are valid reasons.

The exact rules for available callsigns are defined on the FCC website under Rules and Availability. The FCC web site can be confusing to some people, as it is very rules-based, and does not offer many examples or any utilities to help users. A number of free web sites (e.g., Vanity Headquarters, AE7Q, and RadioQTH) have sprung up, some dating back to 1999. These sites offer a variety of features, such as search tools, sorted lists, prediction capabilities, help files, message boards, and the like, all intended to help someone understand the vanity process and request a new callsign.

Due to the popularity of vanity calls, and the lack of region restriction, it is often impossible to tell which region an amateur radio operator using one calls home.

The term "vanity call" is generally not applied to 1 x 2 and similar "special" call signs attained by amateurs from the FCC under special rules in the 1970s and prior decades.

See also

References

  1. ^ "ARTICLE 19 Identification of stations, Section III – Formation of call signs" (PDF). Retrieved 2010-06-21.
  2. ^ International Telecommunication Union country call sign assignments
  3. ^ Korea Contest Club, world's longest seawall
  4. ^ H2T at QRZ.COM
  5. ^ "PIB46" (PDF). Retrieved 2010-06-28.
  6. ^ Irish call book
  7. ^ GB75RD at QRZ.COM
  8. ^ a b "ITU-R M.1172". Life.itu.ch. Retrieved 2010-06-21.
  9. ^ "Miscellaneous abbreviations and signals to be used in radiotelegraphy communications in the maritime mobile service". Life.itu.ch. Retrieved 2010-06-21.
  10. ^ "Canada/United States Operating Agreement". Rac.ca. Retrieved 2010-06-21.
  11. ^ "Lifetime Sample Amateur Radio Licence (including Terms and Conditions) - reduced file size for quicker printing" (PDF). Retrieved 2010-06-21.
  12. ^ Dutch National Day of Monuments
  13. ^ [1]
  14. ^ Korea Contest Club Special Callsign
  15. ^ "Amateur Radio Prefixes". Homepages.tesco.net. Retrieved 2010-06-21.
  16. ^ "call sign oddities". Ac6v.com. Retrieved 2010-06-21.
  17. ^ "Amateur radio prefixes". Homepages.tesco.net. Retrieved 2010-06-21.
  18. ^ "Sovereign Military Order Of Malta - 1A4A". Hamgallery.com. Retrieved 2010-06-28.
  19. ^ "1B/G7PAF". Homepage.ntlworld.com. Retrieved 2010-06-28.
  20. ^ "Western Sahara - S07U". Hamgallery.com. Retrieved 2010-06-28.
  21. ^ "Unverified Operation - Principality of Sealand - S1AD". Hamgallery.com. Retrieved 2010-06-28.
  22. ^ "Spratly Islands - 1S1RR". Hamgallery.com. Retrieved 2010-06-28.
  23. ^ "http://www.arrl.org/country-lists-prefixes DXCC Country list". Arrl.org. Retrieved 2010-06-28. {{cite web}}: External link in |title= (help)
  24. ^ "DXCC rules". Arrl.org. Retrieved 2010-06-28.
  25. ^ "RSGB Islands on the Air". Rsgbiota.org. Retrieved 2010-06-28.