What is 2-way, 3-way, 4-way matching? How is this set-up?

2-way matching verifies that Purchase order and invoice information match within your tolerances as follows: 
Quantity billed <= Quantity Ordered 
Invoice price <= Purchase order price 
(<= sign is used because of tolerances) 

3-way matching verifies that the receipt and invoice information match with the quantity tolerances defined: 
Quantity billed <= Quantity received 

4-way matching verifies that acceptance documents and invoice information match within the quantity tolerances defined: 
Quantity billed <= Quantity accepted. 
(Acceptance is done at the time of Inspecting goods). 

Whether a PO shipment has 2-way, 3-way or 4-way matching can be setup in the Shipment Details zone of the Enter PO form (character) 
Receipt required Inspection required Matching 
YesYes4-way 
YesNo 3-way 
No No 2-way 

What are the documents not supported in PBWC?

Following document types are not supported in PBWC : 
Planned PO 
Local Blanket Agreement 
Local Contract Agreement 
Scheduled Releases 
BPA Releases 
Quotations 
RFQs 

Are Preferences supported in PBWC?

Preferences are not supported in PBWC

Way to define the dependent valueset so that at the time of defining the values for dependent value set value against a independent value set, default values should not appear

1.First create independent valueset,enter the values for the same.
2.Then create dependent valueset,add the indenpendent valuset to this.
3.Enter the default value from the one which you had defined in step1.

GBPA/BPA/SPO which are outcome of a Sourcing RFQ doesn't get defaulted the default contract template

GBPA / BPA / Standard PO which are outcome of a Sourcing RFQ doesn't get defaulted the default contract template even if the profile option 'PO: Auto Apply Default Contract Template' is set to Yes.

PO's autocreated from Requisition don't have contract template attached automatically

When a PO is created from Purchase Requisition via 'CreatePO' workflow, the contract template is not assigned to the PO even profile option 'PO: Auto Apply Default Contract Templates' is set to yes.

This is Bug in R12 onward  and ER is already raised with Oracle development. Bug Reference: 7521651

Express Receiving does not support entering DFF

Express Receiving does not support entering DFF