Our client has just asked about it:
According to the recommendations of tax authorities, foreign currency credit invoices should be entered into the system with the currency rate of the invoice date.
If we make a credit note via operations menu, then the currency exchange rate of the original invoice is copied into the credit invoice.
If I change the rate to the correct one in the credit invoice, then we get an error "Record cannot be saved. Received amount 119,60 is greater than invoice open amount 113,74".
I guess workaround is to enter a credit note without specifying a credited invoice.
Just curious: are accounting rules in other countries different than ours?