"Containment" is in the eye of the beholder
simple words like "must not burst its cases" are a little more descriptive.
Then the conditions of the event are certainly relevant. Such as to whether we're talking high energy multiple particles capable of penetrating a pressure surface behind which are lots of important stuff to fly the aircraft.
Each event must be examined by itself and more importantly combinations such as an uncontainment resulting in :
a loss of flamable fluid
a fire
multiple engine involvement (pilot workload issues)
Multiple systems beyond the single engine (ex, a system in a wing or tail section not associated with the engine itself)
Obviously some of these are aircraft specific.
More importantly the follow on issue is the corrective action.