Change Order Template PDF - Setup?

Summary:

There seems to be a difference between the layouts you can choose of a PO and a Change Order (Procurement Business Function Setup page).

Content (required):

In the Configure Procurement Business Function setup task, on Document Types tab, there is the possibility to select your custom PO layout.

I see there's also a 'Change Order Template' field that can be chosen. By default something is filled in, but I have no idea where this layout comes from (which seeded report?).

To my knowledge, any Change Order on a PO also takes the PO layout (Document Layout).

So what is the use of this field?