Command, control, and communication (C3) systems in Army combat vehicles set the stage for improved awareness of the tactical situation, enhancing the capability to implement changes in mission plans to exploit improved awareness. Reaping these benefits requires training in a collective context, because C3 is inherently a collective activity. This requirement makes it necessary for trainers to consider the stream of digital messages among nodes and operator interactions with systems--adding to the observation requirements that already burden collective trainers. Further, collective trainers must address the fact that many leaders view digital training as a detractor to unit training. The U.S. Army's III Corps identified the need for guidance on how trainers can provide units with diagnostic feedback. The project team used observations, interviews, and literature reviews to identify fifty digital proficiency performance goals arranged into nine topical areas (e.g., apply situational awareness in maneuver decisions) to be addressed by measurement guidance. The measurement guidance developed for each performance goal included a description of its tactical significance, the echelon(s) to be observed, tactical events that should trigger observations, and data to be applied in assessing performance. This approach is designed to help reduce trainer workloads by focusing on high-payoff digital activities. In describing data requirements, the team gave special attention to the possibility of using automated systems to collect and present information regarding the content of digital messages and operator interactions with digital systems to reduce the need for trainers to track these aspects of the situation on their own. The measurement guidance evolved into laminated, pocket-sized products that were distributed to leaders in the 4^th Infantry Division and 1^st Cavalry Division to support digital training. The product is also being used to define the information displays that need to be produced by digital after action review systems addressing digital data streams and operator interactions.