Post

White - No information available about a specific threat. It can also mean "situation stable"

Black - There has been an assessment made that there is the possibility of an attack, but no defined target. It can also mean "possible civil unrest", meaning safety cannot be guaranteed.

Special black - There is an increased likelihood of an attack, but no defined target. It can also mean "potential terrorist threat".

amber - There has been specific information received and there is a substantial threat to government targets. It can also mean "high alert", which could be a transition to war.

Red - Information has been received about an attack on a specific target. It can also mean "red alert", meaning Rhodesia is at war, especially if there is a likelihood of a nuclear strike