For Pre operation triggers we want to enforce a particular convention or style of usage for ClearCase. To do this we place a trigger that occurs before an operation, to make sure that all ClearCase users follow this convention. For example makes sure that the names of newly created labels adhere to a particular convention.
Post operation triggers perform an action after a ClearCase operation, to ensure that the action occurs in conjunction with the operation. For instance, you may want an e-mail notification sent after check-in or check-out. Following is a list of triggers that perform common post-operation actions.