Which term should be used to denote that tasks are completed and the officer can copy a message?

The term that should be used to indicate that tasks are completed and the officer is available to receive and copy a message is "In service." This terminology signifies that the officer is actively ready to engage in communication and can respond to further instructions or messages.

When an officer is "in service," it implies that they are on duty and prepared to take action as needed, without any outstanding tasks hindering their availability. It is crucial in communication protocols to have clear terminology that conveys the current status of law enforcement personnel, ensuring that dispatchers and other units can effectively coordinate and relay important information.

The other terminologies do not convey the same readiness for communication. "Out of service" indicates that the officer is unavailable for communication or tasks. "Affirmative" is typically a response to indicate agreement or acknowledgment but does not directly indicate the status of being ready to receive tasks or messages. "Busy" suggests that the officer is currently engaged in a task and unable to take on further communications at that moment. Thus, the term "in service" is the optimal choice for denoting readiness to receive messages.