Not sure what you mean.
The code above is produced by the eCart shipping rules interface. It looks to me like it is called inside the shipping function:
<%
function xxCart_DefineRules()
xxCart.Discounts = Array()
xxCart.Charges = Array()
xxCart.Tax = Array()
xxCart.Shipping = Array()
xxCart.ShippingIsTaxed = true
'Discounts
xxCart.Discounts = WA_eCart_AddRule(xxCart.Discounts, Unescape("Wholesale%20Discount"), true, "WAEC_xxCart_WholesaleDiscount")
'Charges
'Tax
xxCart.Tax = WA_eCart_AddRule(xxCart.Tax, Unescape("Sales%20Tax"), true, "WAEC_xxCart_SalesTax")
'Shipping
xxCart.Shipping = WA_eCart_AddRule(xxCart.Shipping, Unescape("shipgeneral"), true, "WAEC_xxCart_shipgeneral")
xxCart.Shipping = WA_eCart_AddRule(xxCart.Shipping, Unescape("shipcan"), true, "WAEC_xxCart_shipcan")
end function
%>
Sorry if I'm not understanding what you are asking