Which maintenance notification indicates equipment utilization?

The maintenance notification that indicates equipment utilization is represented by D1. This notification is part of the maintenance management system and is specifically categorized to track the actual usage of equipment. By utilizing the D1 maintenance notification, commanders and maintenance personnel can assess how much equipment is being used and can make informed decisions regarding maintenance schedules, equipment readiness, and resource allocation.

This tracking is crucial to ensure that the equipment is maintained at the right intervals, thereby enhancing operational efficiency and readiness. Understanding equipment utilization allows for better forecasting and planning, ultimately leading to improved mission success and resource management.

When considering the other options, while they all pertain to different maintenance tasks or statuses, they do not specifically relate to the measurement of equipment utilization. Thus, D1 stands out as the correct choice in the context of indicating utilization.