Hello.

I also would like to know how to assign a class to the account "Exchange Gain Or Loss"

You asked "Where", well I would like to assign a class every time, but at this moment the most important is at the time of the payment, I mean, when the account appear in a cash movement (I am only using multi-currency in sales)  because we use Cash Accounting Method. But it could be necessary also at the time of the invoice.

Thanks for your help.