In a previous study, we found that users‟ trust in and reliance on an individual combat identification system is influenced by the system‟s reliability as well as users‟ awareness of the reliability. In this exploratory study we test the effects of design features of the same system on users‟ target identification performance as well as their trust in and reliance on the system. In a simulated task environment, we varied the automation activation mode (i.e., automatic vs. manual) and the presentation of the “unknown” feedback (i.e., explicit vs. implicit). Participants responded fastest when the “unknown” feedback was provided automatically with explicit indication. In addition, participants trusted the explicit “unknown” feedback more than the implicit feedback. However, neither reliance behavior nor identification accuracy changed significantly across conditions. This study has implications for the design of combat identification systems to achieve appropriate trust. In addition, the results suggest that when studying trust in automation using a simulation, it is important to simulate the design features.