How VAT is calculated or where it will come in picture in P2P cycle?

We have completed the VAT setup on the India Localisation.

I am referring the India_Localization_VAT_URM.pdf. ( Doc ID 334823.1 ) for the setup.

I am seeking information about:

1. Item Classification for VAT in PO-AP cycle

What attributes are needed to define for the Items in PO-AP cycle so that VAT is recoverable in the Transaction.

General Item like Chair, Furniture Computer Peripherals. etc

2. Where does the VAT (Tax Lines comes)
As per my knowledge it is needed to be entered by selecting the "Manage Tax" in Purchase order screen or Purchase Requisition screen.

By doing this might be Value Added Tax will come into the Transaction.