|U.S. Defense Department
Terrorist Threat Conditions
Threatcon Normal -- No threat of terrorist activity is present.
Threatcon Alpha -- There is a general threat of possible terrorist activity against installations, building locations, and/or personnel, the nature and extent of which is unpredictable.
Threatcon Bravo -- There is an increased and more predictable threat of terrorist activity although no particular target has been identified.
Threatcon Charlie -- An incident has occurred or intelligence has been received indicating that some form of terrorist action is imminent.
Threatcon Delta -- A terrorist attack has occurred or intelligence has been received that action against a specific location is likely.