Notification history

 Hi All,

I have question regarding PO Approval workflow process. On Required PO Approval Notification , internal name: PO_PO_APPROVE, Message Name= Approve PO, i can find on the notification email the notification history like below.....but on FYI Notification, i cannot find something like this even the message body similar (at the bottom i can find &ACTION_HISTORY)....Could some body tell me on which variable below message will be kept? or on which table i can find such information....because on table PO_ACTION_HISTORY i only can find action code SUBMIT, FORWARD and APPROVED for this PO....cannot find action code for DELEGATE. Thank you.