Field help (CURTYP9) 

This field contains the exchange rate type used to convert the values into the management currency of the plan.
It is not modifiable on the context plans Accounting and financial nor on the IAS/IFRS plan.
When the Depreciation basis origin of the plan has the value IAS/IFRS, the exchange rate type is filled by default by the type defined at the level of the IAS/IFRS valuation on the Principal tab ; otherwise, it is filled in with the type defined at the level of the context definition which the plan belongs to. It remains modifiable.