These are known in the LinnLinn configurator as "Promotional Shipping discount offered" and "Shipping discount Profile ID", in both domestic and international details.



These function as the equivalent of "Additional Price" on the shipping service when different items are bought.



For example:

2 black T-Shirt postage cost = Postage Price + Additional Price

1 red T-Shirt and 1 black T-Shirt = postage price + "price calculated in shipping discount profile"



This suggestion is that the Domestic Profile ID and International Profile ID should be stored in Extended Properties of an inventory item.

This has now been done - Yay!