Selling indirect costs (selling overheads) are costs that are incurred in order to attract and retain customers. Together with administrative and distribution overheads they form non-production indirect costs (non-production overheads).
Selling overheads can include for example:
Selling overheads are in most accounting systems (or even in all?) treated as period costs and booked immediately to profit & loss statement.
This is also the case under IAS 2 – Inventory.