Suppression
There are times when systems are offline where you don't want alarms to appear.
Agency allows you to specify alerts that supress other alerts - preventing them from appearing when people look at your alert list.
For example, an alert that your power level is low shouldn't appear if the entire system is off.
By creating an alert to detect that the system has been shut down, you can then supress a range of other alerts that would otherwise be just creating useless noise by reporting problems where none exist.