This indicator is used to specify if the previous expression is expressed in a currency, where there is then the possibility to give the currency by calculate expression, as well as the common currency in which it should be converted.
The conversion is made at the historic rate defined on the reference date for the triggering event, the exchange rate type used for the conversion being defined by the parameter CHGTYP (the first type if nothing is defined).
Thus it is possible to get amount totals expressed in a homogenous fashion.