Many amateur radio operators are heard calling "Break" incorrectly.
Break should only be used to signify there is high priority / emergency traffic. For example, a QSO is in progress between two or more stations and another station needs to report an accident, incident or other emergency situation that requires assistance.
When the station currently talking stops transmitting the station with the accident report or emergency traffic should key his transmitter and call, “Break" The other stations should immediately acknowledge the breaking station and allow them to pass the urgent traffic.
The term break in amateur radio communications is commonly misused by new operators and old-timers alike. These operators often incorrecly use a "Break" call as a signal that they wish to join the ongoing conversation, use the frequency to make a contact or to simply make their presence known. For these types of interruptions the operator should simply wait for a gap between transmissions and give their call sign once. When the operators using the frequency are at a suitable breaking point in their conversation, they will acknowledge the new station and call them in.
Most amateur radio operating guides instruct to only use a "Break" call in an emergency or life threatening situation. Many amateur radio clubs, groups and repeater systems have operating procedure guidelines that amateur station operators should follow. These are guidelines and not rules or laws, they are proper etiquette. Operators who do not follow proper etiquette are often frowned upon or ignored by other stations.
To avoid any confusion calling "Break" should only be used in urgent or emergency situations.
If You wish to 'break in' to an ongoing conversation, and there is No accident or emergency assistance required, You should simply give Your callsign once and wait patiently for one of the stations to bring You in.
If the frequency, channel or repeater You wish to call on has no current traffic a "Break" call should only be used in an emergency situation to alert other stations that there is an accident, incident, emergency or life threatening situation requiring urgent assistance.
When calling "Break" in an emergency You should be prepared to give information relating to the type of emergency, the location of the incident and state what assistance is required. This information will enable stations receiving Your emergency Break call to pass the required information to emergency services or other organisations that can provide the required assistance.
73 de MM7WAB