bpstart_notify

as the norm you do not run them - and do not need to.

but sometimes you may need to so something before a job or after a job  runs, these scripts let you do that.

Say you want to backup all the files in one specific directory and after the backup you want to remove them.

in this case you would have a bpend_notify script  so that after the backups are done you could put a command in the script to remove all the files from that directory.

or

say you want to backup some directory but you need rename a file before you start the backup to tape.  in this case you would use the bpstart_notify script so that when the backup job starts it will first run your command to rename the file, then it would do the backup to tape.

and you can use both on the same job.

you can be specific about what jobs run it, by creating a specially named schedule or policy

so say your policy is "myspecialbackup"

you would name your script  bpstart_notify.myspecialbackup  (on windows it would end with .exe)