Final answer:
The J-series message mentioned in the question is a form of communication used in military operations, specifically to exchange tactical information on land points and land tracks.
Step-by-step explanation:
The J-series message referred to in the question is a form of communication used in military operations. The J-series messages are a set of standardized codes and protocols used by the U.S. military to transmit tactical information. The message mentioned in the question, which is used to exchange tactical information on land points and land tracks, is most likely the J-series message known as the J-series 6 (J6) message.