| Name | Description | 
| enter | A managed object became visible to a filter for the first time.
  For instance, this can happen if a virtual machine is added to a
  folder. 
 | 
| leave | A managed object left the set of objects visible to a filter.  For
  instance, this can happen when a virtual machine is destroyed. 
 | 
| modify | A property of the managed object changed its value. 
 |