If a Purchase Requisition is submitted for approval, and the Approver rejects it, GP allows the requisition to be deleted. Having a setup option (like SOP Document ID) to prevent deletions - or require a password - would be ideal.

More detail found at:
https://community.dynamics.com/gp/f/microsoft-dynamics-gp-forum/434386/disabling-delete-action-from-purchase-requisition-entry-window/1194117#1194117