How to setup the mapping from OM to AR interface table

I have setup to 2 price charge for an item .

After the SO is shipped and generated into the AR interface table, the Labour Charge show description QP_NET_PRICE and line type is Freight

I would like to ask :

1, Is there any setting to configurate the mapping of AR interface table ?

2, why the line type is Freight ? is it related to the Pricing Charge Definitions setup ?

3, Is it possible for me to change the logic of description and line type mapping ?

Thanks

Wai