R12.2.4 : AP Invoice Hold Notification

Hi,

1) Where can I find the complete explanation(logic,flow etc) for the Workflow - AP Invoice Hold Notification i.e APINVHDN.wft ?

The user guide and implementation guide gives details of Invoice Approval WF but not APINVHDN in explicit manner .

2)If I have to initiate a customized version of APINVHDN.wft, how can that be achieved ?

The "Invoice Hold and Release Names" window has a checkbox named as "Initiate Workflow", which is supposed to trigger the stanadard workflow ?

3)As per standard functionality, in what all situations can the the workflow APINVHDN.wft be initiated ?

Regards,

Amol