Doubts on Item Validation Org, On-hand quantity form, Customer Ordereable flag

Dear Friends,

Request your help in clarifying the below doubts for better understanding of the subject.

1. Item Validation Org system parameter in Order Management:

• What is the significance of item validation org system parameter and why exactly is this required?
• While entering orders, will oracle look for item attributes in Item validation org or shipping organization or both? As per the documentation, it looks for attributes in Item validation org. At the time of pick confirmation and ship confirmation material transactions will happen in shipping org. If Oracle doesn't do any validations on item attributes (like Inventory item, transactable, reservable etc ...) in shipping org at the time of entering or booking the order, how can material transactions be posted into shipping org at the time of pick / ship confirmation?