A task alert is a some check that is run against a specific task. The result of this check is a traffic light metaphor:
red - a problem
amber - a warning
green - fine
A text reason for a red or an amber result is also available.
Task alerts can be run in two places within Epic, dependent on their configuration:
Epic has several built-in task alerts. However the real power of alers come form you defining additional ones useful to yourself through a custom plug-in.