"Alert suppression" suppresses all alerts of this type if there is a match to the rule there. it doesn't suppress just an instance of the alert.
The alert manager evaluates the tabs from left to right:
- get the set of objects that have the alert on them
- remove the set of objects that have the alert reset (so an object that matched both the trigger and reset will get removed); also get the set of objects that were triggered and are /now/ reset.
- check the alert supression tab, if the rule matches stop processing
- check the time of day, if the rule matches stop processing
- do the trigger actions
- do the reset actions
[[I don't know what alert sharing does]]