marginal /absorption costing

Non-production costs are never included in the valuation of inventory, whether it is marginal or absorption costing. However, with marginal costing, the contribution is the selling price less all variable costs (whether production or non-production). All of this is covered in the free Paper F2 lectures on marginal and absorption costing. Although it is assumed knowledge for Paper F5, in Paper F5 you do not get pure absorption vs marginal costing question.