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@JoshuaCarroll
Last active July 7, 2025 17:34
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Regular expression (regex) for non-US amateur radio call signs
All amateur radio call signs:
[a-zA-Z0-9]{1,3}[0-9][a-zA-Z0-9]{0,3}[a-zA-Z]
Non-US call signs:
\b(?!K)(?!k)(?!N)(?!n)(?!W)(?!w)(?!A[A-L])(?!a[a-l])[a-zA-Z0-9][a-zA-Z0-9]?[a-zA-Z0-9]?[0-9][a-zA-Z0-9][a-zA-Z0-9]?[a-zA-Z0-9]?[a-zA-Z0-9]?\b
US call signs:
^[AKNW][A-Z]{0,2}[0-9][A-Z]{1,3}$
@shrop
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shrop commented Dec 11, 2022

@JoshuaCarroll Just saw your comment. Learning Flutter and making a simple call sign lookup iOS and Android app.

@JoshuaCarroll
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Very cool! Thanks for sharing!

@mlforcada
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According to the Radio Regulations of the ITU, Section III, Article 19, a regular expression for callsigns is:

([BFGKIMNRW]|[0-9][A-Z]|[A-Z][0-9]|[A-Z][A-Z])[0-9][0-9A-Z]*[A-Z]

This, of course, leaves some call signs that are or have been used such as D4A, JY1, 7Q1, or 3DA0RS.

I have not included the prefixes used when operating abroad such as in CT7/EA5IYL or suffixes such as /P, /M, /MM, /B, or /3.

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