ERP 9 Supplier Approval

I am trying to figure out Approved Suppliers. We want to know if with the right settings, Epicor will prevent a PO being entered from a supplier that is not approved.

I see Part Class approved supplier - will not work for what we need.
I see Approved Supplier in Supplier Maintenance
I see Approved Supplier in Supplier Parts

Will any method above prevent a PO from being entered?

Thanks in advance.

The “Approved” checkbox in Supplier Maintenance, if unchecked, will prevent any POs from being created to that Supplier.