Item Category

Hi Experts,

Pls guide me on following points

1. can we use one item catagory for diff tran type. for example can we assign ietm catagory(TAN) for tran types like oppt,quotation, order in item catagory determination.

2. We define Item category group and can assign multiple item categories to it. When we enter item category group in produt master which item category is determined, in transaction? (does it have any sequence for that)

3. Can you put some light on Item category Usage?

Thanks in advance.

Regards

Kushal