Wartime reserve modes abbreviated as WARM are military procedures held in reserve for wartime or emergency use. They concern the characteristics and operating procedures of sensor, communications, navigation aids, threat recognition, weapons, and countermeasures systems. Since the military effectiveness of these procedures links to them being unknown to or misunderstood by opposing commanders before they are used, stopping their use by making them reserved has the effect of ensuring they remain effective by making it impossible for them to be known about in advance by such opposing commanders . This prevents them being exploited or neutralized.