Restrict PO creation for vendor on hold

How to restrain user from creating PO when vendor is put on hold.
If not then how it could be restricted from printing final PO

I have come across the same problem. I set the item restrictions to I on the supplier master (f0401.a6edf2) and then in the item restrictions list, leave the list blank. When a user tries to enter an item onto a purchase order, item restrictions prevent the item from being purchased.