What would an observer use to communicate the need for a specific target description in the MTO?

In the context of artillery operations, an observer uses a change to call for fire to communicate the need for a specific target description in the Mission Task Order (MTO). This change allows the observer to provide detailed information about a new or additional target, including its location, type, and target indicators.

When the team is already engaged in fire support and there is a need to refine or specify the target data further—such as changing the target coordinates, describing the target types (e.g., stationary vehicles, troops in the open)—the observer effectively uses the call for fire format to relay this information clearly and accurately. This process ensures that the artillery units can adjust their responses according to the updated intelligence or operational needs while maintaining the coherence and effectiveness of the fire mission.