The recover stage is represented by a pentagon 
. When an exception is raised, the process will first attempt to jump to the first recover stage within the same block. Should it not find any, then it will look for a recover block on the same subpage. If it can't find any, then it will look for a recover stage on the Main page. If no recover stages are found, the process will simply terminate. This process of looking for recover stages from the subpage to the Main page is called bubbling.
Once in the recover stage, the process is in exception mode. At this point, you will execute steps to attempt to handle the error.
