Field help (CURSRH) 

The information specified in this field comes from the delivery showing the currency of the net price in the delivery line. It is in fact possible to carry out a return for delivery lines that have different currencies.
If it is a direct return, the net price being blank, the currency does not have any significance and is not entered. When the return has as its origin a direct supplier return, the currency of the return line is the currency of the supplier return.