You can find this section under Loyalty Schemes > Excluded Products in the IRP Admin left navigation menu.
You can exclude products from being eligible in loyalty schemes. You can do this on a brand / category level or a combination of certain brands and categories.
The main LoyaltySchemesExcludedProducts.aspx page appears as follows:
You use the boxes to select the categories and brands that you want to exclude from Loyalty Schemes. See the How To Guide in this section for more details.