Headers to be the same style.Remove extra diagram.
Looks good
A Print Buyer MAY decide to modify or cancel a confirmed PurchaseOrder.
Looks good, although I guess I'm wondering a bit about the usage "Print Buyer's client"...
@Graham Mann, your changes look good, but I think you missed required upper-case changes in sections 6.5.6 and 6.5.7.
Headers to be the same style.
Remove extra diagram.