The FCC is the government authority that oversees amateur radio. They look at amateur radio to be self-policing and look to the Amateur Radio Relay League (ARRL) to work with amateurs to set guidelines for the amateur community in this capacity. The ARRL’s Amateur Radio Operating Procedures publication states, “It’s important not to use the word break to join a conversation unless you want to use the repeater to help in an emergency.” In fact, question T3C01 in the Technician Class Question Pool, which is the source for questions on the licensing examination for the entry level amateur radio license asks “What is the proper way to break into a conversation between two stations that are using the frequency? The answer is “Say your call sign between their transmissions.”
These guidelines should also be followed for simplex operation. With simplex operation there is no ownership of repeater so there is no organization in charge of such equipment, thus no guidance document. Again, as there are no hard rules to avoid confusion proper etiquette would be to only use break in urgent or emergency situations.
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