Understanding PO Approval Emails

Hi all!

I am needing assistance understanding the PO Approval Email process.  Currently our system is using a message definition - PO_EMAIL_PO_APPROVAL - that is used in AppPackage SCM_PO_EMC.OUTBOUND.formGenerator.OnExecute.  However, I see that there is a PO Approval Generic Template that the system is not using.  Can anyone explain the difference between the two?  I believe the Generic Template will better fit our needs.  How can we utilize the template over the message definition?

To give some context, we would like to remove the URL address from the email that is sent to the approver when a PO is sent to them for approval.  I was able to eliminate the URL by modifying the message definition and PeopleCode, but in place of the URL is text that says '[Submit]'.  You cannot click on it; it is not a link.  But we would like to remove the text to prevent confusion.