Answer: 

This is the total of any other changes that impacts your stock value. This includes (but is not limited to) costs related to importing stock for new products, costs created during the assembly process, and costs differences between warehouses when doing transfers.

Additional Information:

"Plus other costs" is not a single transaction, it is a combination of Import, Assembly, and Transfer transactions that is calculated as follows:
plus Other Costs = (Closing SOH - Opening SOH) - (Total Transaction Value, i.e. Import Cost, Assembly Cost and Transfer Cost)

As this is accumulated over a period from multiple sources, there is no single transaction breakdown of it.