What term should be written or stamped on correspondence that has not received a response in a reasonable time?

The term that should be written or stamped on correspondence that has not received a response in a reasonable time is "TRACER." This term indicates that the sender is requesting a follow-up on the correspondence to ensure that it has been received and that a response is forthcoming. It serves as an alert to the recipient that the matter requires attention and is pending a reply.

Using "TRACER" helps maintain an efficient correspondence system by tracking outstanding communications. This is crucial in the context of military operations, where timely responses can be vital for decision-making and mission continuity. It emphasizes the importance of accountability in communication, ensuring that no correspondence is overlooked or forgotten.

The other terms—"FOLLOW UP," "DEFERRED," and "PENDING"—do carry meanings related to awaiting responses or actual status updates, but they do not specifically convey the same urgency or tracking function that "TRACER" does in official correspondence protocols. "FOLLOW UP" can refer generally to any subsequent actions, while "DEFERRED" implies a postponement, and "PENDING" suggests something is awaiting completion but lacks the directive quality of a "TRACER."