Call signs are identification codes used during radio communication. They are particularly important to the shipping industry, the airline industry and amateur radio operators, although radio stations also have a call sign. Call signs are always issued by the government. In the Caribbean Netherlands, this is done by the Authority of Digital Infrastructure.
Call signs for the Caribbean Netherlands start with PJ4 (Bonaire), PJ5 (Sint Eustatius) or PJ6 (Saba). The first three characters of the call sign are referred to as the ‘prefix’. The letters or numbers that follow are referred to as the ‘suffix’.
Amateur radio operators from another country can use their own call sign if they possess a valid licence. But they must use the extension /PJ4 for Bonaire, /PJ5 for Sint-Eustatius and /PJ6 for Saba. Read more about the requirements here.